Method of manufacturing semiconductor device, substrate processing apparatus, substrate processing system and non-transitory computer-readable recording medium

ABSTRACT

A thin film having excellent etching resistance and a low dielectric constant is described. A method of manufacturing a semiconductor device includes forming a thin film on a substrate, removing first impurities containing H 2 O and Cl from the thin film by heating the thin film at a first temperature higher than a temperature of the substrate in the forming of the thin film, and removing second impurities containing a hydrocarbon compound (C x H y -based impurities) from the thin film in which heat treatment is performed at the first temperature by heating the thin film at a second temperature equal to or higher than the first temperature.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims foreign priority under 35 U.S.C. §119(a)-(d) toApplication Nos. JP 2013-057173 filed on Mar. 19, 2013; JP2014-020046filed on Feb. 5, 2014; and JP2014-025790 filed on Feb. 13, 2014,entitled “Method of Manufacturing Semiconductor Device, SubstrateProcessing Apparatus, Substrate Processing System and Non-TransitoryComputer-Readable Recording Medium,” the entire contents of each ofwhich are hereby incorporated by reference.

FIELD OF THE INVENTION

The present invention relates to a method of manufacturing asemiconductor device, a substrate processing apparatus, a substrateprocessing system, and a non-transitory computer-readable recordingmedium.

BACKGROUND

There are cases in which a process of forming a thin film such as asilicon oxide film on a substrate by supplying a source gas containing apredetermined element such as silicon, an oxidizing gas, or the like tothe substrate is performed as a process of manufacturing a semiconductordevice. In such instances, film forming can be achieved at a relativelylow temperature using, for example, a catalyst gas, thereby improving aheat history and the like received by the semiconductor device.

SUMMARY

When forming a thin film on a substrate, there is a case in whichresistance against wet etching is improved by allowing, for example,carbon to be contained in the thin film, and film quality is improved byreducing a dielectric constant of the film.

However, there is a case in which a sufficient amount of carbon isdifficult to be contained in the film or impurities such as water aremixed in the film under a relatively low temperature. Thus, there arisesa problem that the thin film of a low dielectric constant havingsufficient etching resistance cannot be formed.

It is an object of the present invention to provide technologies whichform a thin film of a low dielectric constant having excellent etchingresistance.

According to one aspect of the present invention, there is provided amethod of manufacturing a semiconductor device, including: (a) forming athin film on a substrate; (b) removing first impurities containing H₂Oand Cl from the thin film by heating the thin film at a firsttemperature higher than a temperature of the substrate in the step (a);and (c) removing second impurities containing a hydrocarbon compoundfrom the thin film by heating the thin film at a second temperatureequal to or higher than the first temperature after performing the step(b).

According to another aspect of the present invention, there is provideda substrate processing apparatus including: a processing chamberconfigured to accommodate a substrate; a processing gas supply systemconfigured to supply a processing gas into the processing chamber toform a thin film on the substrate; a heater configured to heat thesubstrate in the processing chamber; and a control unit configured tocontrol the processing gas supply system and the heater to perform (a)forming the thin film on the substrate by supplying the processing gasto the substrate in the processing chamber, (b) removing firstimpurities containing H₂O and Cl from the thin film by heating the thinfilm at a first temperature higher than a temperature of the substratein the step (a), and (c) removing second impurities containing ahydrocarbon compound from the thin film by heating the thin film at asecond temperature equal to or higher than the first temperature afterperforming the step (b).

According to still another aspect of the present invention, there isprovided a substrate processing system including: a first substrateprocessing unit configured to form a thin film on a substrate; and asecond substrate processing unit configured to perform heat treatment onthe thin film, wherein the first substrate processing unit includes: afirst processing chamber configured to accommodate a substrate; aprocessing gas supply system configured to supply a processing gas intothe first processing chamber; and a first control unit configured tocontrol the processing gas supply system to form the thin film on thesubstrate by supplying the processing gas to the substrate in the firstprocessing chamber; and wherein the second substrate processing unitincludes: a second processing chamber configured to accommodate thesubstrate; a heater configured to heat the substrate in the secondprocessing chamber; and a second control unit configured to control theheater to perform (a) removing first impurities containing H₂O and Clfrom the thin film by heating the thin film at a first temperaturehigher than a temperature of the substrate in a process of forming thethin film in a state in which the second processing chamber accommodatesthe substrate on which the thin film is formed, and (b) removing secondimpurities containing a hydrocarbon compound from the thin film byheating the thin film at a second temperature equal to or higher thanthe first temperature after performing the step (a).

According to yet another aspect of the present invention, there isprovided a non-transitory computer-readable recording medium storing aprogram that causes a computer to execute: (a) forming a thin film on asubstrate in a processing chamber; (b) removing first impuritiescontaining H₂O and Cl from the thin film by heating the thin film at afirst temperature higher than a temperature of the substrate in thesequence (a); and (c) removing second impurities containing ahydrocarbon compound from the thin film by heating the thin film at asecond temperature equal to or higher than the first temperature afterperforming the sequence (b).

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic configuration diagram illustrating a verticalprocessing furnace of a substrate processing apparatus according to afirst embodiment of the present invention, and a verticalcross-sectional diagram illustrating a portion of the processingfurnace.

FIG. 2 is a schematic configuration diagram illustrating a verticalprocessing furnace of a substrate processing apparatus according to afirst embodiment of the present invention, and a cross-sectional diagramtaken along line A-A of FIG. 1 illustrating a portion of the processingfurnace.

FIG. 3 is a schematic configuration diagram illustrating a controller ofa substrate processing apparatus according to a first embodiment of thepresent invention, and a block diagram illustrating a control system ofthe controller.

FIGS. 4A and 4B are diagrams illustrating gas supply timing in filmforming sequences according to a first embodiment of the presentinvention and a modification example thereof, wherein FIG. 4A is adiagram illustrating a sequence example according to the firstembodiment and FIG. 4B is a diagram illustrating a sequence exampleaccording to the modification example.

FIGS. 5A and 5B are diagrams illustrating catalysis of a thin filmforming process according to a first embodiment of the presentinvention, wherein FIG. 5A is a diagram illustrating catalysis in Step 1a and FIG. 5B is a diagram illustrating catalysis in Step 2 a.

FIGS. 6A through 6C are diagrams illustrating gas supply timing in filmforming sequences according to a second embodiment of the presentinvention and modification examples thereof, wherein FIG. 6A is adiagram illustrating a sequence example according to the secondembodiment of the present invention, FIG. 6B is a diagram illustrating asequence example according to Modification Example 1, and FIG. 6C is adiagram illustrating a sequence example according to ModificationExample 2.

FIGS. 7A and 7B are diagrams illustrating gas supply timing in filmforming sequences according to a third embodiment of the presentinvention, wherein FIG. 7A is a diagram illustrating a sequence exampleof forming a stacked film and 7 b shows a sequence example of forming alaminated film.

FIGS. 8A and 8B are diagrams illustrating timing for gas supply and RFpower supply in film forming sequences according to modificationexamples of a third embodiment of the present invention, wherein FIG. 8Ais a diagram illustrating a sequence example of forming a stacked filmand FIG. 8B is a diagram illustrating a sequence example of forming alaminated film.

FIGS. 9A through 9F are diagrams illustrating chemical structuralformulas of various kinds of silanes used as a source gas, andillustrate chemical structural formulas of each of BTCSM, BTCSE, TCDMDS,DCTMDS, HCDS, and BDEAS.

FIGS. 10A through 10F are diagrams illustrating names, chemicalcompositional formulas, chemical structural formulas, and aciddissociation constants of various kinds of amines used as a catalystgas, and illustrate names, chemical compositional formulas, chemicalstructural formulas, and acid dissociation constants of each of annularamine, TEA, DEA, MEA, TMA, and MMA.

FIGS. 11A through 11C are graphs according to embodiments of the presentinvention, wherein FIG. 11A is a diagram illustrating a relativedielectric constant of a SiOC film before and after heat treatment, FIG.11B is a diagram illustrating a wet etching rate of a SiOC film beforeand after heat treatment, and FIG. 11C is a diagram illustratingtemperature dependence of heat treatment of the wet etching rate of theSiOC film.

FIGS. 12A through 12C are graphs illustrating a desorption spectrum byTDS of a SiOC film formed before heat treatment by film formingsequences according to a first embodiment of the present invention,wherein FIG. 12A is a graph illustrating a desorption spectrum of H₂O,FIG. 12B is a graph illustrating a desorption spectrum of Cl, and FIG.12C is a graph illustrating a desorption spectrum of C₂H₂.

FIG. 13 is a diagram illustrating an evaluation result according to anembodiment of the present invention and a table illustrating variouscomparisons between a SiOC film of Sample 1 and a SiOC film of Sample 2.

FIGS. 14A through 14D are diagrams illustrating a temperature controlsequence of a heat treatment process when a second temperature is higherthan a first temperature, and FIGS. 14B to 14D are diagrams illustratingmodification examples of themselves.

FIG. 15 is a diagram illustrating a temperature control sequence of aheat treatment process when a second temperature is equal to a firsttemperature.

FIGS. 16A and 16B are diagrams illustrating an evaluation resultaccording to an embodiment of the present invention, wherein FIG. 16A isa graph illustrating a wet etching rate of a SiOC film of Samples 1 to 6and FIG. 16B is a table illustrating comparison between heat treatmentconditions of the respective Samples.

FIG. 17 is a diagram illustrating an evaluation result according to anembodiment of the present invention and a graph illustrating a relativedielectric constant of a SiOC film of Samples 1 to 8 and of a SiOC filmof Samples 9 and 10.

DETAILED DESCRIPTION First Embodiment

Hereinafter, a first embodiment of the present invention will bedescribed with reference to the accompanying drawings.

(1) Entire Configuration of Substrate Processing Apparatus

As shown in FIG. 1, a processing furnace 202 includes a heater 207 as aheating means (heating mechanism). The heater 207 has a cylindricalshape, and is vertically installed on a heater base (not shown) as aholding plate by being supported thereby. The heater 207 also functionsas an activation mechanism (excitation unit) of activating (exciting) agas by heat as will be described later.

A reaction tube 203 is disposed inside the heater 207 concentrically tothe heater 207. The reaction tube 203 is made of a heat-resistantmaterial such as quartz (SiO₂), silicon carbide (SiC), etc., forexample, and is formed into a cylindrical shape, with an upper endclosed and a lower end opened. A manifold 209 (inlet flange) is arrangedat a lower side of the reaction tube 203 concentrically to the reactiontube 203. The manifold 209 is made of a metal such as stainless steel orthe like, and formed in a cylindrical shape whose upper end and lowerend are opened. The upper end of the manifold 209 is engaged with thelower end of the reaction tube 203 to support the reaction tube 203. AnO ring 220 a as a seal member is provided between the manifold 209 andthe reaction tube 203. The reaction tube 203 is vertically provided insuch a manner that the manifold 209 is supported by the heater base. Aprocessing vessel (reaction vessel) is mainly constituted of thereaction tube 203 and the manifold 209. A processing chamber 201 isformed in a cylinder hollow part of the processing vessel, so thatwafers 200 as substrates can be accommodated by a boat 217 to bedescribed later in a state of being vertically arranged in multiplestages in a horizontal posture.

Nozzles 249 a to 249 c are provided so as to pass through a side wall ofthe manifold 209 in the processing chamber 201. Gas supply pipes 232 ato 232 c are respectively connected to the nozzles 249 a to 249 c. Gassupply pipes 232 d to 232 f are connected to the gas supply pipe 232 a.Gas supply pipes 232 g and 232 h are connected to the gas supply pipe232 b. A gas supply pipe 232 i is connected to the gas supply pipe 232c. In this manner, three nozzles 249 a to 249 c and a plurality of gassupply pipes 232 a to 232 i are provided in the processing vessel, and aplurality of kinds of gases may be supplied into the processing chamber201.

Mass flow controllers (MFC) 241 a to 241 i as a flow rate controller(flow rate control unit) and valves 243 a to 243 i as an opening/closingvalve are provided on the gas supply pipes 232 a to 232 i sequentiallyfrom an upstream direction. Further, gas supply pipes 232 j to 232 l forsupplying an inert gas are connected to a downstream side of the valves243 a to 243 c of the gas supply pipes 232 a to 232 c. MFCs 241 j to 241l and valves 243 j to 243 l are provided on the gas supply pipes 232 jto 232 l sequentially from the upstream direction.

The nozzles 249 a and 249 c are respectively connected to front ends ofthe gas supply pipes 232 a and 232 c. As shown in FIG. 2, the nozzles249 a and 249 c are provided in an arc-shaped space between an innerwall of the reaction tube 203 and the wafers 200, extending from a lowerpart to an upper part of the inner wall of the reaction tube 203, so asto rise toward an upper part of a stacking direction of the wafers 200.Namely, the nozzles 249 a and 249 c are respectively provided in aregion horizontally surrounding a wafer arrangement region, at a sidepart of the wafer arrangement region in which the wafers 200 arearranged, along the wafer arrangement region. Each of the nozzles 249 aand 249 c is formed as an L-shaped long nozzle, with its horizontal partprovided so as to pass through a side wall of the manifold 209, and withits vertical part provided so as to rise from at least one end side ofthe wafer arrangement region toward the other end side. Gas supply holes250 a and 250 c for supplying a gas, are provided on a side face of thenozzles 249 a and 249 c. The gas supply holes 250 a and 250 c are openedto face a center of the reaction tube 203, so that the gas can besupplied toward the wafers 200. A plurality of gas supply holes 250 aand 250 c are provided extending from a lower part to an upper part ofthe reaction tube 203, each of them having the same opening area andprovided at the same opening pitch.

The nozzle 249 b is connected to a front end of the gas supply pipe 232b. The nozzle 249 b is provided in a buffer chamber 237 which is a gasdispersion space. As shown in FIG. 2, the buffer chamber 237 is providedin the arc-shaped space between the inner wall of the reaction tube 203and the wafers 200, extending from the lower part to the upper part ofthe inner wall of the reaction tube 203, along the stacking direction ofthe wafers 200. Namely, the buffer chamber 237 is provided in the regionhorizontally surrounding the wafer arrangement region, at the side partof the wafer arrangement region, along the wafer arrangement region. Gassupply holes 250 d for supplying a gas, are provided on an end portionof a wall adjacent to the wafers 200 of the buffer chamber 237. Each gassupply hole 250 d is opened to face the center of the reaction tube 203,so that the gas can be supplied toward the wafers 200. A plurality ofgas supply holes 250 d are provided extending from the lower part to theupper part of the reaction tube 203, each of them having the sameopening area and provided at the same opening pitch.

The nozzle 249 b is provided on the end portion at an opposite side tothe end portion where the gas supply holes 250 d of the buffer chamber237 is provided, extending to the upper part from the lower part of theinner wall of the reaction tube 203, so as to rise toward the upper partof the stacking direction of the wafers 200. Namely, the nozzle 249 b isprovided in a region horizontally surrounding the wafer arrangementregion, at the side part of the wafer arrangement region, along thewafer arrangement region. The nozzle 249 b is formed as an L-shaped longnozzle, with its horizontal part provided so as to pass through the sidewall of the manifold 209, and with its vertical part provided so as torise from at least one end side of the wafer arrangement region towardthe other end side. Gas supply holes 250 b for supplying a gas, areprovided on a side face of the nozzle 249 b. Each gas supply hole 250 bis opened to face a center of the buffer chamber 237. Similarly to thegas supply holes 250 d, a plurality of gas supply holes 250 b areprovided, extending to the upper part from the lower part of thereaction tube 203. Each of the plurality of gas supply holes 250 b maybe opened in the same opening area at the same opening pitch from theupstream side (lower part) to the downstream side (upper part) when adifferential pressure is small between inside of the buffer chamber 237and inside of the processing chamber 201. On the other hand, when thedifferential pressure is large between inside of the buffer chamber 237and inside of the processing chamber 201, each opening area of the gassupply holes 250 b may become gradually large or each opening pitchthereof may become gradually small, toward the downstream side from theupstream side.

By adjusting the opening area and the opening pitch of each of theplurality of gas supply holes 250 b as described above from the upstreamside to the downstream side, a gas whose flow rate is adjusted to beapproximately the same, although there is a difference in a flowvelocity, is sprayed from each of the gas supply holes 250 b. Then,since the gas sprayed from each of the gas supply holes 250 b isintroduced once into the buffer chamber 237, a difference in the flowvelocity of the gas is made uniform in the buffer chamber 237. Namely,the gas sprayed into the buffer chamber 237 from each of the gas supplyholes 250 b is sprayed into the processing chamber 201 from theplurality of gas supply holes 250 d, after a particle velocity of eachgas is relaxed in the buffer chamber 237. Thus, the gas sprayed into thebuffer chamber 237 from each of the gas supply holes 250 b becomes thegas having a uniform flow rate and flow velocity, when being sprayedinto the processing chamber 201 from each of the gas supply holes 250 d.

As described above, in the present embodiment, the gas is transportedthrough the nozzles 249 a to 249 c and the buffer chamber 237 which aredisposed inside the arc-shaped and vertically long space which isdefined by the inner wall of the reaction tube 203 and the end portionof the plurality of stacked wafers 200, namely, a cylindrical space.Then, the gas is initially sprayed into the reaction tube 203 in thevicinity of the wafers 200 from the gas supply holes 250 a to 250 dopened in the nozzles 249 a to 249 c and the buffer chamber 237. Then, amain flow of the gas inside the reaction tube 203 is made in a directionparallel with the surface of the wafers 200, namely, a horizontaldirection. By the above-described configuration, gases may be uniformlysupplied to each of the wafers 200, and uniformity of a film thicknessof a film formed on each of the wafers 200 may be improved. The gasflowing onto the surface of the wafers 200, namely, a residual gas afterreaction flows in a direction of an exhaust opening, namely, an exhaustpipe 231 to be described later. However, a direction in which theresidual gas flows is appropriately specified by a position of theexhaust opening, and is not limited in a vertical direction.

As a source gas which contains a predetermined element, carbon (C), anda halogen element and has a chemical bond of the predetermined elementand carbon (C), an alkylene halosilane source gas which contains Si asthe predetermined element, an alkylene group, and a halogen group andhas a chemical bond of Si and C (Si—C bond) is supplied into theprocessing chamber 201 from the gas supply pipe 232 a through the MFC241 a, the valve 243 a, and the nozzle 249 a. The alkylene group is afunctional group obtained by removing two hydrogens (H) from a chainsaturated hydrocarbon (alkane) represented as a general formulaC_(n)H_(2n+2) and is an assembly of atoms represented as a generalformula C_(n)H_(2n). The alkylene group includes a methylene group, anethylene group, a propylene group, a butylene group, and the like. Thehalogen group includes a chloro group, a fluoro group, a bromo group,and the like. Namely, halogen elements such as chlorine (Cl), fluorine(F), bromine (Br), and the like are included in the halogen group.

As the alkylene halosilane source gas, a source gas containing Si, amethylene group (—CH₂—) as the alkylene group, and a chloro group (Cl)as the halogen group, namely, a chlorosilane source gas containing themethylene group or a source gas containing Si, an ethylene group(—C₂H₄—) as the alkylene group, and the chloro group (Cl) as the halogengroup, namely, a chlorosilane source gas containing the ethylene groupmay be used. As the chlorosilane source gas containing the methylenegroup, for example, a methylenebis(trichlorosilane) gas, namely, abis(trichlorosilyl)methane ((SiCl₃)₂CH₂, abbreviated as BTCSM) gas andthe like may be used. As the chlorosilane source gas containing theethylene group, for example, an ethylenebis(trichlorosilane) gas,namely, a 1,2-bis(trichlorosilyl)ethane ((SiCl₃)₂C₂H₄, abbreviated asBTCSE) gas and the like may be used.

As shown in FIG. 9A, BTCSM includes one methylene group as the alkylenegroup from a chemical structural formula of BTCSM (from one molecule).Two bonds included in the methylene group are respectively bonded withSi to form a Si—C—Si bond.

As shown in FIG. 9B, BTCSE includes one ethylene group as the alkylenegroup from one molecule. Two bonds included in the ethylene group arerespectively bonded with Si to form a Si—C—C—Si bond.

As a source gas which contains a predetermined element, carbon (C), andhalogen elements and has a chemical bond of the predetermined elementand C, an alkyl halosilane source gas which contains Si as thepredetermined element, an alkyl group, and a halogen group and has achemical bond of Si—C is supplied into the processing chamber 201 fromthe gas supply pipe 232 d through the MFC 241 d, the valve 243 d, andthe nozzle 249 a. The alkyl group is a functional group obtained byremoving one hydrogen (H) from a chain saturated hydrocarbon representedas a general formula C_(n)H_(2n+2), and is an assembly of atomsrepresented as a general formula C_(n)H_(2n+1). The alkyl group includesa methyl group, an ethyl group, a propyl group, a butyl group, and thelike. The halogen group includes a chloro group, a fluoro group, and abromo group, and the like, namely, halogen elements such as Cl, F, Br,and the like.

As the alkyl halosilane source gas, a source gas containing, forexample, Si, a methyl group (—CH₃—) as the alkyl group, and a chlorogroup (Cl) as the halogen group, namely, a chlorosilane source gascontaining the methyl group may be used. As the chlorosilane source gascontaining the methyl group, for example, a1,1,2,2-tetrachloro-1,2-dimethyldisilane ((CH₃)₂Si₂Cl₄, abbreviated asTCDMDS) gas, a 1,2-dichloro-1,1,2,2-tetramethyldisilane ((CH₃)₄Si₂Cl₂,abbreviated as DCTMDS) gas, a 1-monochloro-1,1,2,2,2-pentamethyldisilane((CH₃)₅Si₂Cl, abbreviated as MCPMDS) gas, and the like may be used. Thealkyl halosilane source gas such as the TCDMDS gas, the DCTMDS gas, orthe like is different from the alkylene halosilane source gas such asthe BTCSE gas, BTCSM gas, or the like, and is a gas including a Si—Sibond, namely, a source gas which contains a predetermined element and ahalogen element and has a chemical bond between predetermined elements.

As shown in FIG. 9C, TCDMDS contains two methyl groups as an alkyl groupfrom one molecule. Each bond included in two methyl groups is bondedwith Si to form a Si—C bond. The TCDMDS is a deriviative of disilane,and includes a Si—Si bond. Namely, TCDMDS includes a Si—Si—C bond inwhich Sis are bonded and Si and C are bonded.

As shown in FIG. 9D, DCTMDS includes four methyl groups as an alkylgroup from one molecule. Each bond included in four methyl groups isbonded with Si to form a Si—C bond. The DCTMDS is a derivative ofdisilane and includes a Si—Si bond. Namely, the DCTMDS includes aSi—Si—C bond in which Sis are bonded and Si and C are bonded.

As a source gas containing Si as a predetermined element and a halogenelement, for example, a halosilane source gas which contains Si and ahalogen element and has a chemical bond between Si and Si (Si—Si bond)is supplied into the processing chamber 201 through the MFC 241 e, thevalve 243 e, and the nozzle 249 a from the gas supply pipe 232 e.

As the halosilane source gas, for example, a source gas which containsSi and a chloro group (Cl) as the halogen element and has a Si—Si bond,namely, a chlorosilane source gas may be used. The chlorosilane sourcegas is a silane source gas containing a chloro group, and a source gascontaining at least Si and Cl as the halogen element. Namely, achlorosilane source may be a kind of a halide. As the chlorosilanesource gas supplied from the gas supply pipe 232 e, for example, ahexachlorodisilane (Si₂Cl₆, abbreviated as HCDS) gas may be used.

As shown in FIG. 9E, HCDS includes two Sis and six chloro groups fromone molecule. As a source gas containing Si and a halogen element, aninorganic source gas such as tetrachlorosilane, namely, a silicontetrachloride (SiCl₄, abbreviated as STC) gas, a trichlorosilane(SiHCl₃, abbreviated as TCS) gas, a dichlorosilane (SiH₂Cl₂, abbreviatedas DCS) gas, a monochlorosilane (SiH₃Cl, abbreviated as MCS) gas, or thelike other than the HCDS gas may be used.

As a source gas which contains Si as a predetermined element, C, andnitrogen (N) and has a chemical bond between Si and N (Si—N bond), anaminosilane source gas as a source gas containing Si and an amino group(amine group) is supplied into the processing chamber 201 from the gassupply pipe 232 f through the MFC 241 f, the valve 243 f, and the nozzle249 a.

The aminosilane source gas is a silane source gas containing the aminogroup, and is a source gas which includes the amino group containing atleast Si, C, and N. As the aminosilane source gas being supplied fromthe gas supply pipe 232 f, for example, a bis(diethylamino)silane(Si[N(C₂H₅)₂]₂H₂, abbreviated as BDEAS) gas may be used.

As shown in FIG. 9F, BDEAS includes one Si and two amino groups from onemolecule. As a source gas which contains Si, C, and N and has a Si—Nbond, an organic source gas such as a tris(diethylamino)silane(SiH[N(C₂H₅)₂]₃, abbreviated as 3DEAS) gas, atetrakis(diethylamino)silane (Si[N(C₂H₅)₂]₄, abbreviated as 4DEAS) gas,a tris(dimethylamino)silane (Si[N(CH₃)₂]₃H, abbreviated as 3DMAS) gas, atetrakis(dimethylamino)silane (Si[N(CH₃)₂]₄, abbreviated as 4DMAS) gas,or the like other than the BDEAS gas may be used.

Here, the source gas indicates a source in a gas state, for example, agas obtained by vaporizing a source in a liquid state under ordinarytemperature and normal pressure, or a source in a gas state underordinary temperature and normal pressure. In the present invention,cases in which the term “source” is used include a case in which thesource gas means a “liquid source in a liquid state,” a case in whichthe source gas means a “source gas in a gas state,” or a case in whichthe source gas means the both. When a liquid source in a liquid stateunder ordinary temperature and normal pressure such as BTCSM, BTCSE,TCDMDS, DCTMDS, HCDS, and BDEAS is used, the liquid source is vaporizedby a vaporizer or a vaporizing system such as a bubbler, and is suppliedas the source gas (BTCSM gas, BTCSE gas, TCDMDS gas, DCTMDS gas, HCDSgas, and BDEAS gas).

A gas containing oxygen (O) (oxygen-containing gas) as an oxidizing gasis supplied into the processing chamber 201 from the gas supply pipe 232b through the MFC 241 b, the valve 243 b, the nozzle 249 b, and thebuffer chamber 237. As the oxidizing gas being supplied from the gassupply pipe 232 b, for example, vapor (H₂O gas) may be used. Inaddition, with regard to supply of the H₂O gas, an oxygen (O₂) gas and ahydrogen (H₂) gas may be supplied to an external combustion device,which is not shown, and combusted to generate and supply an H₂O gas.

A gas containing oxygen (O) (oxygen-containing gas) as an oxidizing gasis supplied into the processing chamber 201 from the gas supply pipe 232g through the MFC 241 g, the valve 243 g, the nozzle 249 b, and thebuffer chamber 237. As the oxidizing gas being supplied from the gassupply pipe 232 g, for example, an ozone (O₃) gas may be used.

A gas containing oxygen (O) (oxygen-containing gas) as an oxidizing gasis supplied into the processing chamber 201 from the gas supply pipe 232h through the MFC 241 h, the valve 243 h, the nozzle 249 b, and thebuffer chamber 237. As the gas being supplied from the gas supply pipe232 h, for example, an oxygen (O₂) gas may be used.

As a catalyst gas which promotes decomposition of a source gas andpromotes an oxidation reaction by an oxidizing gas such as an H₂O gas,or the like by weakening a bonding power of an O—H bond included in thesurface of the wafers 200 or a bonding power of an O—H bond included inthe H₂O gas by catalytic action, for example, an amine-based gascontaining, C, N, and H is supplied into the processing chamber 201 fromthe gas supply pipe 232 c through the MFC 241 c, the valve 243 c, andthe nozzle 249 c.

The amine-based gas is a gas containing amine obtained by substitutingat least one H of ammonia (NH₃) with a hydrocarbon group such as analkyl group or the like. As shown in FIGS. 10A through 10F, variousamines used as the catalyst gas contain N including a lone electronpair, and an acid dissociation constant (hereinafter, referred to as“pKa”) thereof is about 5 to 11. The pKa is one of indexesquantitatively indicating the strength of acid, and means that anequilibrium constant Ka in a dissociation reaction in which an H ion isreleased from the acid is indicated by a negative common logarithm. Asthe amine-based gas, a cyclic amine-based gas in which a hydrocarbongroup has a cyclic shape or a chain amine-based gas in which thehydrocarbon group has a chain shape may be used. As the amine-based gasbeing supplied from the gas supply pipe 232 c, for example, a pyridine(C₅H₅N) gas as the cyclic amine-based gas may be used.

As shown in FIG. 10A, as the cyclic amine-based gas, a pyridine (C₅H₅N,pKa=5.67) gas, an aminopyridine (C₅H₆N₂, pKa=6.89) gas, a picoline(C₆H₇N, pKa=6.07) gas, a lutidine (C₇H₉N, pKa=6.96) gas, a piperazine(C₄H₁₀N₂, pKa=9.80) gas, a piperidine (C₅H₁₁N, pKa=11.12) gas, and thelike may be used. The cyclic amine-based gas may be referred to as aheterocyclic compound whose cyclic structure is constituted of multiplekinds of elements of C and N, namely, a nitrogen-containing heterocycliccompound.

As a catalyst gas having the same catalysis as in the cyclic amine-basedgas, an amine-based gas containing C, N, and H is supplied into theprocessing chamber 201 from the gas supply pipe 232 i through the MFC241 i, the valve 243 i, and the nozzle 249 c. As the amine-based gasbeing supplied from the gas supply pipe 232 i, a chain triethylamine((C₂H₅)₃N, abbreviated as TEA) gas may be used.

As shown in FIGS. 10B to 10F, as the chain amine-based gas, atriethylamine ((C₂H₅)₃N, abbreviated as TEA, pKa=10.7) gas, adiethylamine ((C₂H₅)₂NH, abbreviated as DEA, pKa=10.9) gas, amonoethylamine ((C₂H₅)NH₂, abbreviated as MEA, pKa=10.6) gas, atrimethylamine ((CH₃)₃N, abbreviated as TMA, pKa=9.8) gas, amonomethylamine ((CH₃)NH₂, abbreviated as MMA, pKa=10.6) gas, and thelike may be used.

The amine-based gas acting as a catalyst gas may be referred to as anamine-based catalyst gas. As the catalyst gas, a non-amine-based gas,namely, an ammonia (NH₃, pKa=9.2) gas or the like may be used other thanthe above-described amine-based gas.

There is a case in which a part of a molecular structure of theexemplified catalyst gas is decomposed in a thin film forming processwhich will be described later. Strictly speaking, the gas whose part ischanged before and after such a chemical reaction is not a “catalyst.”However, in the present invention, a material substantially acting asthe catalyst in such a manner that most of the material is notdecomposed even though a part of the material is decomposed in a processof the chemical reaction and a speed of the reaction is changed isreferred to as the “catalyst.”

A nitrogen (N₂) gas as an inert gas is supplied into the processingchamber 201 from the gas supply pipes 232 j to 232 l through the MFC 241j to 241 l, the valves 243 j to 243 l, the gas supply pipes 232 a to 232c, the nozzles 249 a to 249 c, and the buffer chamber 237, respectively.

The N₂ gas acts as a purge gas, and also acts as an oxygen-free gaswithout containing oxygen (O) that generates an oxygen-free atmospherewhich will be described later. When the N₂ gas is used as theoxygen-free gas, there is a case in which the N₂ gas acts as a heattreatment gas or an annealing gas. As the inert gas, the purge gas, andthe oxygen-free gas, rare gases such as an argon (Ar) gas, a helium (He)gas, a neon (Ne) gas, a xenon (Xe) gas, and the like other than the N₂gas may be used.

When the above-described gases flow from each of the gas supply pipes, asource gas supply system for supplying a source gas is mainlyconstituted of gas supply pipes 232 a, 232 d, 232 e, and 232 f, MFCs 241a, 241 d, 241 e, and 241 f, and valves 243 a, 243 d, 243 e, and 243 f.The nozzle 249 a may be included in the source gas supply system. Thesource gas supply system may be referred to as a source supply system.The source gas supply system may be considered to be an assembly of aplurality of supply lines (supply systems) which supply a plurality ofkinds of source gases as element sources of mutually different elementsor a plurality of kinds of source gases whose molecular structures aredifferent from each other. Namely, the source gas supply system may bean assembly of a BTCSM gas supply line mainly constituted of the gassupply pipe 232 a, the MFC 241 a, and the valve 243 a, a TCDMDS gassupply line mainly constituted of the gas supply pipe 232 d, the MFC 241d, and the valve 243 d, an HCDS gas supply line mainly constituted ofthe gas supply pipe 232 e, the MFC 241 e, and the valve 243 e, and aBDEAS gas supply line mainly constituted of the gas supply pipe 232 f,the MFC 241 f, and the valve 243 f. The nozzle 249 a may be included ineach of the supply lines.

As described above, the plurality of supply lines constituting thesource gas supply system are configured to supply the plurality of kindsof source gases as the element sources of the mutually differentelements or the plurality of kinds of source gases whose molecularstructures are different from each other. In addition, each of thesource gases has a different molecular structure, namely, a differentchemical structural formula. Composition or component of each source gasmay be different. The source gases having mutually different molecularstructures have different chemical properties. Therefore, byappropriately selecting kinds of source gases in accordance with adesired film formation process as will be described later, variouscomposition ratios and a thin film having excellent reproducible filmquality may be formed for a general purpose using a single substrateprocessing apparatus.

In addition, an oxidizing gas supply system is mainly constituted of thegas supply pipes 232 b, 232 g, and 232 h, the MFCs 241 b, 241 g, and 241h, and the valves 243 b, 243 g, and 243 h. The nozzle 249 b and thebuffer chamber 237 may be included in the oxidizing gas supply system.The oxidizing gas supply system may be referred to as an oxidizer supplysystem. The oxidizing gas supply system may be considered to be anassembly of a plurality of supply lines (supply systems) which supply aplurality of kinds of oxidizing gases whose molecular structures aredifferent from each other. Namely, the oxidizing gas supply system maybe an assembly of an H₂O gas supply line mainly constituted of the gassupply pipe 232 b, the MFC 241 b, and the valve 243 b, an O₃ gas supplyline mainly constituted of the gas supply pipe 232 g, the MFC 241 g, andthe valve 243 g, and an O₂ gas supply line mainly constituted of the gassupply pipe 232 h, the MFC 241 h, and the valve 243 h. The nozzle 249 bor the buffer chamber 237 may be included in each of the supply lines.

As described above, the plurality of supply lines constituting theoxidizing gas supply system are configured to supply the plurality ofkinds of oxidizing gases whose molecular structures are different fromeach other. In addition, each of the oxidizing gases has a differentmolecular structure, namely, a different chemical structural formula.Composition or component of each oxidizing gas may be different. Theoxidizing gases having mutually different molecular structures havedifferent chemical properties. Therefore, by appropriately selectingkinds of oxidizing gases in accordance with a desired film formationprocess, various composition ratios and a thin film having excellentreproducible film quality may be formed for a general purpose using asingle substrate processing apparatus.

In addition, a catalyst gas supply system is mainly constituted of thegas supply pipes 232 c and 232 i, the MFCs 241 c and 241 i, and thevalves 243 c and 243 i. The nozzle 249 c may be included in the catalystgas supply system. The catalyst gas supply system may be considered tobe an assembly of a plurality of supply lines (supply systems) whichsupply a plurality of kinds of catalyst gases whose molecular structuresare different from each other. Namely, the catalyst gas supply systemmay be an assembly of a pyridine gas supply line mainly constituted ofthe gas supply pipe 232 c, the MFC 241 c, and the valve 243 c, and a TEAgas supply line mainly constituted of the gas supply pipe 232 i, the MFC241 i, and the valve 243 i. The nozzle 249 c may be included in each ofthe supply lines. The pyridine gas or the TEA gas may be considered tobe an amine-based gas as a catalyst, namely, an amine-based catalyst gasas will be described later. Hereinafter, the catalyst gas supply systemwhich supplies various amine-based catalyst gases is referred to as anamine-based catalyst gas supply system.

As described above, the plurality of supply lines constituting thecatalyst gas supply system are configured to supply the plurality ofkinds of catalyst gases whose molecular structures are different fromeach other. In addition, each of the catalyst gases has a differentmolecular structure, namely, a different chemical structural formula.Composition or component of each of the catalyst gases may be different.The catalyst gases having mutually different molecular structures havedifferent chemical properties. Therefore, by appropriately selectingkinds of catalyst gases in accordance with a desired film formationprocess as will be described later, various composition ratios and athin film having excellent reproducible film quality may be formed for ageneral purpose using a single substrate processing apparatus.

In addition, an inert gas supply system is mainly constituted of the gassupply pipes 232 j to 232 l, the MFCs 241 j to 241 l, and the valves 243j to 243 l. The nozzles 249 a to 249 c and the buffer chamber 237 on adownstream side of a connection portion with the gas supply pipes 232 jto 232 l in the gas supply pipes 232 a to 232 c may be included in theinert gas supply system. The inert gas supply system may be consideredto be an assembly of a plurality of supply lines. Namely, the inert gassupply system may be an assembly of an inert gas supply line mainlyconstituted of the gas supply pipe 232 j, the MFC 241 j, and the valve243 j, an inert gas supply line mainly constituted of the gas supplypipe 232 k, the MFC 241 k, and the valve 243 k, and an inert gas supplyline mainly constituted of the gas supply pipe 232 l, the MFC 241 l, andthe valve 243 l. The inert gas supply system also functions as a purgegas supply system and an oxygen-free gas supply system. In addition, theoxygen-free gas supply system constitutes a part of an atmospheregenerating unit that generates an oxygen-free atmosphere which will bedescribed later.

Any one or all of the above-described source gas supply system,oxidizing gas supply system, catalyst gas supply system, and inert gassupply system may be referred to as a processing gas supply system.

As shown in FIG. 2, two rod electrodes 269 and 270 which are constitutedof electric conductors and have a slim and long structure are arrangedin the stacking direction of the wafers 200 extending from the lowerpart to the upper part of the reaction tube 203. Each of the rodelectrodes 269 and 270 is provided in parallel to the nozzle 249 d. Eachof the rod electrodes 269 and 270 is protected by being covered by anelectrode protective tube 275 from the upper part to the lower part. Oneof the rod electrodes 269 and 270 is connected to a high frequency powersource 273 via a matcher 272, and other one is connected to earth as areference electric potential. As a result, plasma is generated in aplasma generation region 224 between the rod electrodes 269 and 270 byapplying high frequency (RF) power between the rod electrodes 269 and270 from the high frequency power source 273 via the matcher 272. Aplasma source as a plasma generator (plasma generation unit) is mainlyconstituted of the rod electrodes 269 and 270 by the electrodeprotective tube 275. The matcher 272 and the high frequency power source273 may be included in the plasma source. The plasma source functions asan activation mechanism (excitation unit) of activating a gas in aplasma state.

The electrode protective tube 275 is configured to insert each of therod electrodes 269 and 270 into the buffer chamber 237 in a state ofbeing isolated from an atmosphere of the buffer chamber 237. Here, if anoxygen concentration of the inside of the electrode protective tube 275is set in the same level as an oxygen concentration of the outside air(atmosphere), the rod electrodes 269 and 270 inserted into the electrodeprotective tube 275 respectively, are oxidized by heat of the heater207. Therefore, by charging or purging the inside of the electrodeprotective tube 275 with the inert gas such as an N₂ gas using an inertgas purge mechanism, the oxygen concentration of the inside of theelectrode protective tube 275 can be lowered, thereby suppressing anoxidation of the rod electrodes 269 and 270.

The exhaust pipe 231 for exhausting the atmosphere in the processingchamber 201 is provided in the reaction tube 203. A vacuum pump 246 as avacuum exhaust device is connected to the exhaust pipe 231, via apressure sensor 245 as a pressure detector (pressure detection unit) fordetecting a pressure in the processing chamber 201, and an auto pressurecontroller (APC) valve 244 as a pressure adjuster (pressure adjustmentunit). The APC valve 244 is configured to perform vacuum exhaust/stop ofvacuum exhaust in the processing chamber 201 by opening and closing thevalve in a state of operating the vacuum pump 246, and is furtherconfigured to adjust the pressure in the processing chamber 201 byadjusting an opening degree of the valve based on pressure informationdetected by the pressure sensor 245 in a state of operating the vacuumpump 246. An exhaust system is mainly constituted of the exhaust pipe231, the APC valve 244, and the pressure sensor 245. The vacuum pump 246may be included in the exhaust system. The exhaust pipe 231 is notlimited to a case of being installed in the reaction tube 203, and maybe installed in the manifold 209 similarly to the nozzles 249 a to 249c.

The atmosphere generating unit that generates an oxygen-free atmospherein the processing chamber 201 is mainly constituted of theabove-described exhaust system and oxygen-free gas supply system. Theexhaust system is configured to set the atmosphere in the processingchamber 201 as the oxygen-free atmosphere with the exhaust system aloneby performing vacuum exhaust on the inside of the processing chamber201, or in conjunction with the oxygen-free gas supply system thatsupplies an oxygen-free gas to the wafers 200 in the processing chamber201.

A seal cap 219 is provided in a lower portion of the manifold 209, as afurnace port lid member capable of air-tightly closing a lower endopening of the manifold 209. The seal cap 219 is configured to abut onthe lower end of the manifold 209 from a vertical lower side. The sealcap 219 is made of a metal such as SUS, and formed into a disc shape. AnO-ring 220 b as a seal member abutted on the lower end of the manifold209 is provided on an upper surface of the seal cap 219. A rotationmechanism 267 for rotating a boat 217 to be described later is installedon an opposite side of the processing chamber 201 across the seal cap219. A rotary shaft 255 of the rotation mechanism 267 passes through theseal cap 219 and is connected to the boat 217. The rotation mechanism267 is configured to rotate the wafers 200 by rotating the boat 217. Theseal cap 219 is configured to be vertically elevated by a boat elevator115 as an elevation mechanism vertically installed outside the reactiontube 203. The boat elevator 115 is configured to load and unload theboat 217 into/from the processing chamber 201 by elevating the seal cap219. Namely, the boat elevator 115 is configured as a transportingdevice (transporting mechanism) for transporting the boat 217 and thewafers 200 supported by the boat 217 to the inside/outside of theprocessing chamber 201.

The boat 217 as a substrate supporting tool is configured to support aplurality of, for example, 25 or 200 sheets of wafers 200 in ahorizontal posture, with centers thereof aligned, vertically arranged inmultiple stages, namely, arranged spaced apart. The boat 217 is made ofa heat-resistant material such as quartz, SiC, or the like. In a lowerportion of the boat 217, a heat insulating plate 218 made of theheat-resistant material such as quartz, SiC, or the like is supported ina horizontal posture in multiple stages. Thus, heat from the heater 207is hardly transmitted to the seal cap 219 side. However, the presentembodiment is not limited to the embodiments described above. Forexample, without providing the heat insulating plate 218 in the lowerportion of the boat 217, a heat insulating cylinder configured as acylindrical member made of a heat-resistant material such as quartz orSiC may be provided.

A temperature sensor 263 as a temperature detector is installed in thereaction tube 203. By adjusting a power supply state to the heater 207based on the temperature information detected by the temperature sensor263, the temperature in the processing chamber 201 is set to have adesired temperature distribution. Similarly to the nozzles 249 a to 249c, the temperature sensor 263 is formed into the L-shape, and isprovided along the inner wall of the reaction tube 203.

As shown in FIG. 3, a controller 121 as a control unit (control means)is configured as a computer including a central processing unit (CPU)121 a, an random access memory (RAM) 121 b, a memory device 121 c, andan I/O port 121 d. The RAM 121 b, the memory device 121 c, and the I/Oport 121 d are configured to perform data exchange with the CPU 121 avia an internal bus 121 e. An input/output device 122 configured as atouch panel, etc., is connected to the controller 121.

The memory device 121 c includes, for example, a flash memory, a harddisk drive (HDD), and the like. A control program for controlling anoperation of the substrate processing apparatus, and a process recipe,etc., indicating a procedure and a condition, etc., of substrateprocessing to be descried later are readably stored in the memory device121 c. The process recipe is a combination of recipes, so that eachprocedure in a substrate processing process such as a thin film formingprocess to be described later is executed by the controller 121 toobtain a specific result, and functions as a program. Hereinafter, theprocess recipe and the control program, etc., are generally simplycalled a program. In the present specification, cases in which the term“program” is used include a case of including only a single processrecipe, a case of including only a control program, or a case ofincluding both of them. The RAM 121 b is configured as a memory area(work area) in which the program and data, etc., read by the CPU 121 aare temporarily stored.

The I/O port 121 d is connected to the MFCs 241 a to 241 l, the valves243 a to 243 l, the pressure sensor 245, the APC valve 244, the vacuumpump 246, the temperature sensor 263, the heater 207, the matcher 272,the high frequency power source 273, the rotation mechanism 267, theboat elevator 115, and the like.

The CPU 121 a is configured to read and execute the control program fromthe memory device 121 c, and is configured to read the process recipefrom the memory device 121 c according to an input, etc., of anoperation command from the input/output device 122. Then, the CPU 121 ais configured to control a flow rate adjustment operation of each kindof gas by the MFCs 241 a to 241 l, an opening/closing operation of thevalves 243 a to 243 l, an opening/closing operation of the APC valve244, a pressure adjustment operation based on the pressure sensor 245 bythe APC valve 244, start/stop of the vacuum pump 246, a temperatureadjustment operation of the heater 207 based on the temperature sensor263, a rotation and rotation speed adjustment operation of the boat 217by the rotation mechanism 267, an elevating operation of the boat 217 bythe boat elevator 115, an impedance adjustment operation by the matcher272, power supply by the high frequency power source 273, and the like,so as to follow the read process recipe.

The controller 121 may be configured not only as a dedicated computer,but also as a general-purpose computer. For example, an external memorydevice 123 (for example, a magnetic tape, a magnetic disc such as aflexible disc and a hard disc, etc., an optical disc such as CD and DVD,etc., an optical magnetic disc such as MO, etc., and a semiconductormemory such as a USB memory and a memory card, etc.) storing theabove-mentioned program is prepared, and by using the external memorydevice 123, the program is installed in the general-purpose computer, tothereby constitute the controller 121 according to this embodiment.However, a means for supplying the program to the computer is notlimited to a case of supplying it through the external memory device123. For example, communication means such as Internet and a dedicatedline, etc., may be used to thereby supply the program not through theexternal memory device 123. The memory device 121 c or the externalmemory device 123 is configured as a computer-readable recording medium.Hereinafter, these are generally simply called a recording medium. Inthe present specification, cases in which the term “recording medium” isused include a case of including only a single memory device 121 c, acase of including only a single external memory device 123, or a case ofincluding both of them.

(2) Thin Film Forming Process

A sequence example of forming a thin film on the substrate as one stepof a manufacturing process of a semiconductor device using theabove-described substrate processing apparatus will be described withreference to FIG. 4A. In the following description, operations ofrespective units constituting the substrate processing apparatus arecontrolled by the controller 121.

In the film forming sequence shown in FIG. 4A, a process of forming asilicon oxide carbon film (hereinafter, referred to as “SiOC film”) as athin film containing Si, O, and C on the wafers 200 by performing apredetermined number of times (n times) a cycle including a process ofsupplying a BTCSM gas as a source gas containing Si, C, and Cl andhaving a Si—C bond to the wafers 200 as the substrate, a process ofsupplying an H₂O gas as an oxidizing gas to the wafers 200, and aprocess of supplying a pyridine gas as a catalyst gas to the wafers 200is performed. The SiOC film may be referred to a SiO film containing Cor a SiO film in which C is doped (added).

At this time, the process of supplying the BTCSM gas is performed in astate in which the process of supplying the pyridine gas has beenperformed, and the process of supplying the H₂O gas is performed in astate in which the process of supplying the pyridine gas has beenperformed.

In addition, after forming the SiOC film, a process of removing firstimpurities from the SiOC film by heating the SiOC film at a firsttemperature higher than a temperature of the wafers 200 in the processof forming the SiOC film, and a process of removing second impuritiesdifferent from the first impurities from the SiOC film on which heattreatment has been performed at the first temperature by heating theSiOC film at a second temperature equal to or higher than the firsttemperature are further performed. The heat treatment is performed underan oxygen-free atmosphere, namely, under the oxygen-free atmospheregenerated by supplying the N₂ gas as an oxygen-free gas to the wafers200.

In addition, in the present embodiment, each process is performed undera non-plasma atmosphere.

Cases in which the term “wafer” is used in the present specificationinclude a case of meaning the “wafer itself,” a case of meaning the“wafer or a laminated body (assembly) of predetermined layers or filmsformed on a surface thereof,” namely, a case of denoting the waferincluding the predetermined layers or films formed on the surfacethereof. In addition, in the present specification, cases in which theterm “the surface of the wafer” is used include a case of meaning a“surface (exposed surface) of the wafer itself” or a case of meaning the“surface of the predetermined layers or films formed on the wafer,namely, the outermost surface of the wafer as a laminated body.”

In the present specification, cases in which “a predetermined gas issupplied to the wafer” is described include a case of meaning that the“predetermined gas is directly supplied to a surface (exposed surface)of the wafer itself” or a case of meaning that the “predetermined gas issupplied to the layers or films formed on the wafer, namely, to theoutermost surface of the wafer as the laminated body.” In addition, inthe present specification, cases in which “predetermined layers (orfilms) are formed on the wafer” is described include a case of meaningthat the “predetermined layers (or films) are directly formed on thesurface (exposed surface) of the wafer itself” or a case of meaning thatthe “predetermined layers (or films) are formed on the layers or filmsformed on the wafer, namely, on the outermost surface of the wafer asthe laminated body.”

In the present specification, a case in which the term “substrate” isused is the same as the case in which the term “wafer” is used, and inthis case, the “wafer” may be substituted with the “substrate” in theabove description.

Wafer Charge and Boat Load

When a plurality of wafers 200 are loaded (wafer charged) in the boat217, the boat 217 that supports the plurality of wafers 200 is elevatedby the boat elevator 115 to be loaded into (boat load) the processingchamber 201 as shown in FIG. 1. In this state, the seal cap 219 sealsthe lower end of the manifold 209 through the O-ring 220 b.

Pressure Adjustment and Temperature Adjustment

The inside of the processing chamber 201, namely, a space in which thewafers 200 are present is vacuum-exhausted by the vacuum pump 246 so asto be set in a desired pressure (vacuum degree). At this time, thepressure in the processing chamber 201 is measured by the pressuresensor 245, and the APC valve 244 is feedback-controlled based on themeasured pressure information. The vacuum pump 246 maintains a state ofbeing operated at all times until at least processing on the wafers 200is completed. In addition, the inside of the processing chamber 201 isheated by the heater 207 so as to be set at a desired temperature. Atthis time, the power supply state to the heater 207 isfeedback-controlled based on the temperature information detected by thetemperature sensor 263 so as to have a desired temperature distribution.Heating of the inside of the processing chamber 201 by the heater 207 iscontinuously performed until at least the processing on the wafers 200is completed. However, in a case of performing the processing on thewafers 200 at room temperature as will be described later, the heatingof the inside of the processing chamber 201 by the heater 207 may not beperformed. Subsequently, rotation of the boat 217 and the wafers 200 bythe rotation mechanism 267 is started. The rotation of the boat 217 andthe wafers 200 by the rotation mechanism 267 is continuously performeduntil at least the processing on the wafers 200 is completed.

SiOC Film Formation Process

Next, the following two steps, namely, Step 1a and Step 2a aresequentially performed.

Step 1a (BTCSM Gas+Pyridine Gas Supply)

The valve 243 a is opened to flow the BTCSM gas into the gas supply pipe232 a. The flow rate of the BTCSM gas is adjusted by the MFC 241 a sothat the BTCSM gas is supplied into the processing chamber 201 from thegas supply hole 250 a and exhausted from the exhaust pipe 231. At thistime, the BTCSM gas is supplied to the wafers 200. Simultaneously atthis time, the valve 243 j is opened to flow the N₂ gas into the gassupply pipe 232 j. The flow rate of the N₂ gas is adjusted by the MFC241 j, so that the N₂ gas is supplied into the processing chamber 201together with the BTCSM gas and exhausted from the exhaust pipe 231.

In addition, the valve 243 c is opened to flow the pyridine gas into thegas supply pipe 232 c. The flow rate of the pyridine gas is adjusted bythe MFC 241 c so that the pyridine gas is supplied into the processingchamber 201 from the gas supply hole 250 c and exhausted from theexhaust pipe 231. At this time, the pyridine gas is supplied to thewafer 200. Simultaneously at this time, the valve 243 l is opened toflow the N₂ gas into the gas supply pipe 232 l. The flow rate of the N₂gas is adjusted by the MCF 241 l so that the N₂ gas is supplied into theprocessing chamber 201 together with the pyridine gas and exhausted fromthe exhaust pipe 231.

In addition, in order to prevent an invasion of the BTCSM gas and thepyridine gas into the buffer chamber 237 or the nozzle 249 b, the valve243 k is opened to flow the N₂ gas into the gas supply pipe 232 k. TheN₂ gas is supplied into the processing chamber 201 through the gassupply pipe 232 b, the nozzle 249 b, and the buffer chamber 237, andexhausted from the exhaust pipe 231.

At this time, the APC valve 244 is properly adjusted to thereby maintainthe pressure in the processing chamber 201 to be a pressure, for examplein a range of 1 to 13,330 Pa, preferably, 133 to 2, 666 Pa. The supplyflow rate of the BTCSM gas controlled by the MFC 241 a is set, forexample in a range of 1 to 2,000 sccm, preferably, 10 to 1,000 sccm. Thesupply flow rate of the pyridine gas controlled by the MFC 241 c is set,for example, in a range of 1 to 2,000 sccm, preferably, 10 to 1,000sccm. The supply flow rate of the N₂ gas controlled by the MFCs 241 j to241 l is set, for example, in a range of 100 to 10,000 sccm. The timerequired for supplying the BTCSM gas and the pyridine gas to the wafers200, namely, the gas supply time (irradiation time) is set, for example,in a range of 1 to 100 seconds, preferably, 5 to 60 seconds.

At this time, the temperature of the heater 207 is set so that thetemperature of the wafers 200 is set, for example, in a range of equalto or higher than room temperature and equal to or less than 150° C.,preferably, equal to or higher than the room temperature and equal to orless than 100° C., and more preferably, equal to or higher than 50° C.and equal to or less than 100° C. In a case in which the catalyst gas isnot supplied while the BTCSM gas is supplied, the BTCSM is difficult tobe chemically adsorbed on the wafers 200 when the temperature of thewafers 200 is less than 250° C., and therefore a practical film formingrate cannot be obtained. As in the present embodiment, by supplying thepyridine gas as the catalyst gas, it is possible to solve this problemeven when the temperature of the wafers 200 is less than 250° C. In thepresence of the pyridine gas, by setting the temperature of the wafers200 to be 150° C. or less or 100° C. or less, the amount of heat appliedto the wafers 200 may be reduced, thereby satisfactorily performingcontrol of thermal history which the wafers 200 receive. In the presenceof the pyridine gas, when the temperature of the wafers 200 is the roomtemperature or higher, the BTCSM may be sufficiently adsorbed on thewafers 200, thereby obtaining a sufficient film forming rate. Therefore,the temperature of the wafers 200 is set, for example, in a range of theroom temperature or higher and 150° C. or less, preferably, the roomtemperature or higher and 100° C. or less, and more preferably, 50° C.or higher and 100° C. or less.

By supplying the BTCSM gas to the wafers 200 under the above-describedcondition, a silicon-containing layer containing C and Cl with athickness about less than one atomic layer to several atomic layers as afirst layer is formed on the wafers 200 (an under layer of its surface).The silicon-containing layer containing C and Cl may be a Si layercontaining C and Cl, or may be an adsorption layer of the BTCSM gas, ormay include both of them.

The Si layer containing C and Cl is a general term including acontinuous layer made of silicon (Si) and containing C and Cl, adiscontinuous layer, and a Si thin film formed by overlap of theselayers and containing C and Cl. The continuous layer made of Si andcontaining C and Cl is also called the Si thin film containing C and Clin some cases. Si forming the Si layer containing C and Cl includes acase that a bond between C and Cl is not completely separated and alsoincludes a case that the bond between C and Cl is completely separated.

The adsorption layer of the BTCSM gas includes an adsorption layer inwhich gas molecules of the BTCSM gas are continuous, and a discontinuousadsorption layer. Namely, the adsorption layer of the BTCSM gas includesan adsorption layer with a thickness of one molecular layer or less thanone molecular layer composed of BTCSM molecules. A chemical structuralformula of the BTCSM molecules forming the adsorption layer of the BTCSMgas is shown in FIG. 9A, and the BTCSM molecules include a case in whicha bond of Si and C is partially separated or a case in which a bond ofSi and Cl is partially separated. Namely, the adsorption layer of theBTCSM gas may be a physical adsorption layer of the BTCSM molecules, maybe a chemical adsorption layer of the BTCSM molecules, or may includeboth of them.

Here, a layer with the thickness less than one atomic layer denotes anatomic layer discontinuously formed, and a layer with the thickness ofone atomic layer denotes an atomic layer continuously formed. A layerwith the thickness less than one molecular layer denotes a molecularlayer discontinuously formed and a layer with the thickness of onemolecular layer denotes a molecular layer continuously formed. Thesilicon-containing layer having C and Cl may include both of the Silayer containing C and Cl and the adsorption layer of the BTCSM gas.However, as described above, with regard to the silicon-containing layerhaving C and Cl, expressions such as “one atomic layer,” “several atomiclayers,” and the like may be used.

When the thickness of the silicon-containing layer having C and Cl asthe first layer formed on the wafers 200 exceeds several atomic layers,an oxidizing action in Step 2a to be described later does not reach thewhole body of the first layer.

Further, a minimum value of the thickness of the first layer that can beformed on the wafer 200 is less than one atomic layer. Therefore, thethickness of the first layer is preferably set in a range of about lessthan one atomic layer to several atomic layers. By setting the thicknessof the first layer to one atomic layer or less, namely, to one atomiclayer or less than one atomic layer, an action of an oxidation reactionin Step 2a to be described later can be relatively increased, and thetime required for the oxidation reaction in Step 2a can be shortened.The time required for forming the first layer in Step 1a can beshortened, too. As a result, a processing time per one cycle can beshortened, and the processing time in total can be shortened. Namely,the film forming rate can also be increased. Further, by setting thethickness of the first layer to one atomic layer or less,controllability of the uniformity of film thickness can also beimproved.

The Si layer containing C and Cl is formed by deposition of Si on thewafer 200 under a condition that the BTCSM gas is self-decomposed,namely, a condition that a thermal decomposition reaction of the BTCSMoccurs. The adsorption layer of the BTCSM gas is formed by adsorption ofthe BTCSM gas on the wafer 200 under a condition that the BTCSM gas isnot self-decomposed, namely, a condition that the thermal decompositionreaction of the BTCSM does not occur. The film forming rate can behigher preferably in a case of forming the Si layer containing C and Clon the wafer 200, than in a case of forming the adsorption layer of theBTCSM gas on the wafer 200. However, in the present embodiment, thetemperature of the wafer 200 is set as a low temperature of, forexample, 150° C. or less, and therefore there is a possibility that acase of forming the adsorption layer of the BTCSM gas on the wafer 200is more advantageous than a case of forming the Si layer containing Cand Cl on the wafer 200. In addition, when the catalyst gas is notsupplied, there is a possibility that a bond for an under layer such asthe surface of the wafer 200 and the like in the adsorption layer of theBTCSM gas or a bond between the BTCSM molecules is more advantageous ina state of physical adsorption, which is weaker than chemicaladsorption, than in a state of the chemical adsorption. That is, whenthe catalyst gas is not supplied, there is a possibility that a mostpart of the adsorption layer of the BTCSM gas may be constituted of thephysical adsorption layer of the BTCSM gas.

The pyridine gas functions as a catalyst gas which weakens a bondingpower of an O—H bond existing on the surface of the wafer 200 to promotedecomposition of the BTCSM gas and promote formation of the first layerby chemical absorption of the BTCSM molecules. For example, as shown inFIG. 5A, the pyridine gas acts on the O—H bond existing on the surfaceof the wafer 200 to weaken the bonding power between O—H. By reactionbetween H with the weakened bonding power and Cl of the BTCSM gas,gaseous substances containing Cl and H such as HCl are generated, and Clis removed from the BTCSM molecules while H is removed from the surfaceof the wafer 200. The BTCSM molecules (halide) from which Cl is removedare chemically adsorbed on the surface of the wafer 200 or the like.Thus, a chemical adsorption layer of the BTCSM gas is formed on thesurface of the wafer 200 or the like.

The pyridine gas weakens the bonding power between O—H due to an actionin which N including a lone electron pair from the pyridine moleculespulls H. The magnitude of the action in which a predetermined compoundcontaining N or the like pulls H uses the above-described aciddissociation constant (pKa) as one of indexes. As described above, thepKa is a constant obtained by indicating the equilibrium constant Ka bya negative common logarithm in a dissociation reaction in which an H ionis released from acid, and a compound having a large pKa has a largestrength of pulling H. For example, by using a compound having at least5 pKa as the catalyst gas, decomposition of the BTCSM gas is promoted topromote formation of the first layer. Meanwhile, when the pKa of thecatalyst gas is excessively large, Cl withdrawn from the BTCSM moleculeand the catalyst gas are bonded with each other, whereby salt (ioncompound) such as ammonium chloride (NH₄Cl) and the like may begenerated to be a particle source. In order to suppress this, the pKa ofthe catalyst gas is adjusted in a range of about 11 or less, preferably,7 or less. The pyridine gas has a relatively large pKa of approximately5.67, and has a strong force to pull H. In addition, since the pKa is 7or less, particles are hardly generated.

Residual Gas Removal

After the first layer is formed, the valve 243 a is closed and thesupply of the BTCSM gas is stopped. In addition, the valve 243 c isclosed and the supply of the pyridine gas is stopped. In this instance,the inside of the processing chamber 201 is vacuum-exhausted by thevacuum pump 246 in a state in which the APC valve 244 is opened, andtherefore the non-reacted BTCSM gas and pyridine gas remaining in theprocessing chamber 201 or the BTCSM gas and pyridine gas obtained aftercontributing to formation of the first layer are eliminated from theinside of the processing chamber 201. In addition, the supply of the N₂gas into the processing chamber 201 is maintained in a state in whichthe valves 243 j to 243 l are opened. The N₂ gas acts as the purge gas,whereby an effect to eliminate the non-reacted BTCSM gas and pyridinegas remaining in the processing chamber 201 or the BTCSM gas andpyridine gas obtained after contributing to formation of the first layermay be increased.

In this instance, the gas remaining in the processing chamber 201 maynot be completely eliminated, and the inside of the processing chamber201 may not be completely purged. When the gas remaining in theprocessing chamber 201 is in a small amount, an adverse effect does notoccur in Step 2a which is subsequently performed. It is not required toadjust the flow rate of the N₂ gas supplied into the processing chamber201 to be a large flow rate, and for example, purge in the same level aswhen the adverse effect in Step 2a does not occur may be performed bysupplying the same amount as a volume of the reaction tube 203(processing chamber 201). In this manner, the inside of the processingchamber 201 is not completely purged, whereby the purge time isshortened to improve the throughput. It is also possible to suppressconsumption of the N₂ gas to a minimum level.

As the source gas, for example, the BTCSE gas, the TCDMDS gas, theDCTMDS gas, and the like may be used other than the BTCSM gas. As thecatalyst gas, for example, cyclic amine-based gases such as anaminopyridine gas, a picoline gas, a lutidine gas, a piperazine gas, apiperidine gas, and the like, chain amine-based gases such as a TEA gas,a DEA gas, an MEA gas, a TMA gas, an MMA gas, and the like, ornon-amine-based gases such as an NH₃ gas and the like may be used otherthan the pyridine gas. As the inert gas, for example, rare gases such asan Ar gas, a He gas, an Ne gas, an Xe gas, and the like may be used.

Step 2a (H₂O Gas+Pyridine Gas Supply)

After Step 1a is completed, the valve 243 b is opened to flow the H₂Ogas into the gas supply pipe 232 b. The flow rate of the H₂O gas isadjusted by the MFC 241 b, so that the H₂O gas is supplied into thebuffer chamber 237 from the gas supply holes 250 b and exhausted fromthe exhaust pipe 231. At this time, the H₂O gas is supplied to the wafer200 under a non-plasma atmosphere. Simultaneously at this time, thevalve 243 k is opened to flow the N₂ gas into the gas supply pipe 232 k.The flow rate of the N₂ gas is adjusted by the MFC 241 k so that the N₂gas is supplied into the processing chamber 201 together with the H₂Ogas and exhausted from the exhaust pipe 231.

In addition, like the supply of the pyridine gas in Step 1a, thepyridine gas is supplied to the wafer 200.

In addition, in order to prevent invasion of the H₂O gas and thepyridine gas into the nozzle 249 a, the valve 243 j is opened to flowthe N₂ gas into the gas supply pipe 232 j. The N₂ gas is supplied intothe processing chamber 201 via the gas supply pipe 232 a and the nozzle249 a, and exhausted from the exhaust pipe 231.

At this time, the APC valve 244 is properly adjusted to thereby maintainthe pressure in the processing chamber 201 to be the pressure, forexample in a range of 1 to 13,330 Pa, preferably, 133 to 2,666 Pa. Thesupply flow rate of the H₂O gas controlled by the MFC 241 b is set, forexample in a range of 1,000 to 10,000 sccm, preferably, 10 to 1,000sccm. The supply flow rate of the pyridine gas controlled by the MFC 241c is set, for example, in a range of 1 to 2,000 sccm, preferably, 10 to1,000 sccm. The supply flow rate of the N₂ gas controlled by the MFCs241 j to 241 l is set, for example, in a range of 100 to 10,000 sccm.The time required for supplying the H₂O gas and the pyridine gas to thewafers 200, namely, the gas supply time (irradiation time) is set, forexample, in a range of 1 to 100 seconds, preferably, 5 to 60 seconds.The temperature of the heater 207 is set such that the temperature ofthe wafer 200 is in a similar temperature zone to the temperature of thewafer 200 in Step 1a, for example, in a range of equal to or higher thanroom temperature and equal to or less than 150° C., preferably, equal toor higher than the room temperature and equal to or less than 100° C.,and more preferably, equal to or higher than 50° C. and equal to or lessthan 100° C.

The H₂O gas supplied into the processing chamber 201 is activated byheat and exhausted from the exhaust pipe 231. At this time, the H₂O gasactivated by heat is supplied to the wafer 200. The gas flowing into theprocessing chamber 201 is the H₂O gas which is thermally activated, andthe BTCSM gas does not flow into the processing chamber 201. Thus, theH₂O gas does not cause a gas phase reaction, is supplied to the wafer200 in a state of being activated, and reacts with at least a part ofthe first layer (silicon-containing layer including C and Cl) formed onthe wafer 200 in Step 1a. Thus, the first layer is thermally oxidizedinto the non-plasma to be converted into a second layer including Si, O,and C, namely, a SiOC layer.

The pyridine gas acts as the catalyst gas which weakens the bondingpower of O—H bond included in the H₂O gas to promote decomposition ofthe H₂O gas and promote a reaction between the H₂O gas and the firstlayer. For example, as shown in FIG. 5B, the pyridine gas acts on theO—H bond included in the H₂O gas to weaken the bonding power betweenO—H. By reaction between H with the weakened bonding power and Clincluded in the first layer formed on the wafer 200, gaseous substancescontaining Cl and H such as HCl are generated, and Cl is desorbed fromthe first layer while H is desorbed from the H₂O molecules. O of the H₂Ogas from which H is desorbed is bonded with Si of the first layer inwhich Cl is desorbed and at least a part of C remains.

In a process of supplying the H₂O gas (process of supplying the H₂O gasand the pyridine gas) in a state in which the supply of the pyridine gasis performed, an supply amount of the pyridine gas to be supplied may beappropriately adjusted in accordance with a desired film composition andthe like. When the supply amount of the pyridine gas is increased,action of the pyridine gas is increased to improve oxidation power ofthe H₂O gas, and a Si—C bond is cut so that C is easily desorbed, andconsequently, a C concentration in the SiOC layer is decreased. When thesupply amount of the pyridine gas is reduced, action of the pyridine gasis weakened to degrade oxidation power of the H₂O gas, and the Si—C bondis easily maintained, and consequently, the C concentration in the SiOClayer is increased. Therefore, by appropriately adjusting the supplyamount of the pyridine gas, the C concentration, a Si concentration, oran O concentration in the SiOC layer, namely, a SiOC film formed bylaminating the SiOC layers may be relatively changed.

The supply amount of the pyridine gas to be supplied in the process ofsupplying the H₂O gas (process of supplying the H₂O gas and the pyridinegas) in a state in which the supply of the pyridine gas has beenperformed, and the supply amount of the pyridine gas to be supplied inthe process of supplying the BTCSM gas (process of supplying the BTCSMgas and the pyridine gas) in the state in which the above-describedsupply of the pyridine gas has been performed may be adjusted separatelyfrom each other. For example, the supply amounts of the pyridine gas inboth processes may be adjusted equally or unequally.

By preparing a plurality of process recipes (programs in which processsequences or process conditions are described) in which the supplyamount or the flow rate of the pyridine gas is set as different numeralvalues in advance, adjustment of the supply amount of the pyridine gasbecomes easy. An operator (operation source) may perform a film formingprocess by appropriately selecting an appropriate process recipe inaccordance with a desired film composition and the like.

As in the present embodiment, when forming the SiOC layer under a lowtemperature condition, for example, of 150° C. or less, impurities(first impurities) such as water (H₂O) or Cl, or hydrocarbon(C_(x)H_(y))-based impurities (second impurities) such as a hydrocarboncompound are easily mixed in the SiOC layer. Namely, the impurities suchas wafer or Cl, or C_(x)H_(y)-based impurities may be largely includedin the SiOC film obtained in such a manner that the SiOC layers arelaminated. The impurities such as water is derived from the H₂O gas usedas the oxidizing gas or water invading from the outside when loading thewafers 200 into the processing chamber 201. The impurities such as Clare derived from Cl in the BTCSM molecules. The C_(x)H_(y)-basedimpurities are derived from C and H from the BTCSM molecules or C and Hfrom the pyridine molecules.

Residual Gas Removal

Next, the valve 243 b is closed and the supply of the H₂O gas isstopped. In addition, the valve 243 c is closed and the supply of thepyridine gas is stopped. At this time, the inside of the processingchamber 201 is vacuum-exhausted by the vacuum pump 246 in a state inwhich the APC valve 244 is opened, and thus the non-reacted H₂O gas orpyridine gas remaining in the processing chamber 201, or the H₂O gas,the pyridine gas, or reaction byproducts obtained after contributing tothe reaction are eliminated from the processing chamber 201. Inaddition, the supply of the N₂ gas into the processing chamber 201 ismaintained in the state in which the valves 243 j to 243 l are opened.The N₂ gas acts as the purge gas, whereby an effect to eliminate, fromthe inside of the processing chamber 201, the non-reacted H₂O gas orpyridine gas remaining in the processing chamber 201, or the H₂O gas,the pyridine gas, or the reaction byproducts obtained after contributingto formation of the second layer may be increased.

At this time, the gas remaining in the processing chamber 201 may not becompletely eliminated, and the inside of the processing chamber 201 maynot be completely purged. When the gas remaining in the processingchamber 201 is in a small amount, an adverse effect does not occur inStep 1a which is subsequently performed. It is not required to adjustthe flow rate of the N₂ gas supplied into the processing chamber 201 tobe a large flow rate, and for example, purge in the same level as whenthe adverse effect in Step 1a does not occur may be performed bysupplying the same amount as the volume of the reaction tube 203(processing chamber 201). In this manner, the inside of the processingchamber 201 is not completely purged, whereby the purge time isshortened to improve the throughput. It is possible to suppressconsumption of the N₂ gas to a minimum level.

As the oxidizing gas, a hydrogen peroxide (H₂O₂) gas, a hydrogen (H₂)gas, a hydrogen (H₂) gas+an oxygen (O₂) gas, a hydrogen (H₂) gas+anozone (O₃) gas, and the like may be used other than the H₂O gas. Inaddition, a gas without containing H, for example, an O₂ gas and thelike may be used alone. As the catalyst gas, the above-described variousamine-based gases or non-amine-based gases may be used other than thepyridine gas. As the inert gas, the above-described various rare gasesmay be used other than the N₂ gas.

According to the present inventor and the like, based on overalljudgment within the gas system and the condition range in the presentembodiment, the pyridine gas is more preferably considered to be thecatalyst gas through each process. Subsequently, the TEA gas ispreferably considered to be the catalyst gas, and subsequently, thepiperidine gas is preferably considered to be the catalyst gas.

Execution of Predetermined Number of Times

The above-described Steps 1a and 2a are set as one cycle, and byexecuting this cycle at least once, namely, a predetermined number oftimes (n times), a predetermined composition and a SiOC film with apredetermined film thickness may be formed on the wafer 200. Theabove-described cycle is preferably repeated a plurality of times.Namely, by making a thickness of the SiOC layer formed per one cyclesmaller than a desired film thickness, the above-described cycle ispreferably repeated the plurality of times until obtaining the desiredfilm thickness.

At this time, by controlling processing conditions such as the pressurein the processing chamber 201, a gas supply time, and the like in eachstep, each element component of the SiOC layer, namely, a ratio of a Sicomponent, an O component, and a C component, namely, a Siconcentration, an O concentration, and a C concentration can be finelyadjusted, and a composition ratio of the SiOC film can be more preciselycontrolled.

When the cycle is executed the plurality of times, a part described as“a predetermined gas is supplied to the wafer 200” in each step after atleast two cycles means that “the predetermined gas is supplied to alayer formed on the wafer 200, namely, the outermost surface of thewafer 200 as a laminated body,” and a part described as “a predeterminedlayer is formed on the wafer 200” means that “the predetermined layer isformed on the layer formed on the wafer 200, namely, on the outermostsurface of the wafer 200 as the laminated body.” This point is the sameas the above. This point is also the same as in other embodiments to bedescribed later.

SiOC Film Modification Process

As described above, impurities such as water or C₁ or C_(x)H_(y)-basedimpurities may be mixed in the SiOC film formed under the lowtemperature condition of 150° C. or less. When these impurities aremixed in the SiOC film, etching resistance of the SiOC film is degraded,and a dielectric constant thereof is increased. Namely, there is a casein which an effect in which C in the film is added cannot be obtained.

Therefore, in the present embodiment, a process (first heat treatmentprocess) of removing the first impurities (impurities such as water, Cl,or the like) from the SiOC film by heating the SiOC film at a firsttemperature higher than the temperature of the wafer 200 in the processof forming the SiOC film; and a process (second heat treatment process)of removing the second impurities (C_(x)H_(y)-based impurities)different from the first impurities from the SiOC film on which heattreatment has been performed by heating the SiOC film at a secondtemperature equal to or higher than the first temperature are performed,and a modification process of removing a plurality of kinds ofimpurities from the SiOC film in at least two stages. Namely, theprocess of modifying the SiOC film so-called an annealing process isperformed in two stages. Hereinafter, a sequence example of the SiOCfilm modification process will be described.

Pressure Adjustment and Temperature Adjustment

The inside of the processing chamber 201, namely, a space in which thewafers 200 exist is vacuum-exhausted by the vacuum pump 246 while theAPC valve 244 is feedback-controlled so as to be set in a desiredpressure (vacuum degree). In addition, the wafer 200 in the processingchamber 201 is heated by the heater 207 so as to obtain a desiredtemperature, namely, the first temperature. At this time, the powersupply state to the heater 207 is feedback-controlled based on thetemperature information detected by the temperature sensor 263 so thatthe inside of the processing chamber 201 has a desired temperaturedistribution. Even in this process, the boat 217 and the wafers 200continue to be rotated by the rotation mechanism 267.

In addition, the inside of the processing chamber 201 is adjusted to anoxygen-free atmosphere by supplying the N₂ gas as the oxygen-free gasinto the processing chamber 201. At this time, the N₂ gas may besupplied using at least one or all of the gas supply pipes 232 j to 232l. Here, the N₂ gas is supplied using, for example, all of the gassupply pipes 232 j to 232 l. Namely, the valves 243 j to 243 l areopened to flow the N₂ gas into the gas supply pipes 232 j to 232 l. Theflow rate of the N₂ gas is adjusted by the MFCs 241 j to 241 l so thatthe N₂ gas is supplied into the processing chamber 201 from the gassupply holes 250 a, 250 c, and 250 d, and exhausted from the exhaustpipe 231. Thus, the inside of the processing chamber 201 becomes an N₂gas atmosphere, namely, an oxygen-free atmosphere. The N₂ gas also actsas a heat treatment gas later.

First Heat Treatment

When the inside of the processing chamber 201 becomes the N₂ gasatmosphere having a desired pressure and the temperature of the wafer200 becomes a desirable temperature, namely, the first temperature, thisstate is maintained for a predetermined time, and first heat treatmentis performed on the SiOC film formed on the wafer 200.

At this time, the APC valve 244 is properly adjusted to thereby maintainthe pressure in the processing chamber 201 to be a pressure, for examplein a range of 133 to 101,325 Pa (1 to 760 Torr), preferably, 10,132 to101,325 Pa (76 to 760 Torr). The supply flow of the N₂ gas controlled bythe MFCs 241 j to 241 l is set in a range of, for example, to 100 to10,000 sccm. The time required for heat treatment on the SiOC film onthe wafer 200 is set as a time in a range, for example, 1 to 60 minutes,preferably, 1 to 30 minutes, and more preferably, 1 to 10 minutes.

At this time, the temperature of the heater 207 is set such that thetemperature of the wafer 200 is a first temperature higher than thetemperature of the wafer 200 in the process of forming theabove-described SiOC film. Specifically, the temperature of the wafer200 is room temperature or a temperature of 150° C. or higher, and forexample, the temperature of the wafer 200 is set to be a temperature ina range of 300° C. or higher and 450° C. or less, preferably 300° C. orhigher and 400° C. or less, and more preferably 300° C. or higher and350° C. or less. In this manner, a temperature range is determined afterconsidering that the impurities such as water or Cl as the firstimpurities are efficiently or sufficiently desorbed and removed from theSiOC film without causing occurrence of an undesirable reaction(oxidization or the like of SiOC film).

FIGS. 12A through 12C are diagrams illustrating a desorption spectrumusing thermal desorption gas spectroscopy (TDS) of the SiOC film beforeheat treatment which is formed by the film forming sequence of thepresent embodiment, wherein FIG. 12A illustrates a desorption spectrumof water (H₂O), FIG. 12B illustrates a desorption spectrum of Cl, andFIG. 12C illustrates a desorption spectrum of C₂H₂. A horizontal axis ofthe FIGS. 12A through 12C indicates a temperature (° C.) of the wafer200 when performing heat treatment, and a vertical axis thereofindicates an ion current value (A).

As shown in FIGS. 12A and 12B, when the temperature of the wafer 200 isbelow 300° C., it is difficult to desorb and remove the impurities suchas water, Cl, or the like, particularly, water from the SiOC film,whereby a modification effect of the SiOC film may be degraded. Forexample, when the temperature of the wafer 200 is 150° C. or less, theimpurities such as water or Cl are hardly desorbed from the SiOC film.The impurities such as water or Cl may be sufficiently desorbed from theSiOC film to be removed by setting the temperature of the wafer 200 tobe 300° C. or higher.

However, when the temperature of the wafer 200 exceeds 450° C., the SiOCfilm may be oxidized by a reaction of water and Cl when water or Cl isdesorbed from the SiOC film. A film shrinking rate of the SiOC film isincreased by the oxidization of the SiOC film.

In addition, when water reacts with Cl in this temperature zone, namely,in the temperature zone exceeding 450° C., HCl is generated, and a Si—Clbond, a Si—H bond, or the like included in the SiOC film may beseparated by the generated HCl. When these bonds are separated, anunnecessary adsorption site is generated in the SiOC film, and thereforere-adsorption of substances (desorbed substances) desorbed from the SiOCfilm onto the adsorption site may be caused. Namely, the desorbedsubstances from the SiOC film are adsorbed onto Si including a danglingbond (non-bond) in such a manner that a bond with Cl or H is separated.The bond of the Si formed in this manner and the desorbed substances isunstable and weak. Thus, the desorbed substances do not becomecomponents constituting the SiOC film but remain in the SiOC film asimpurities. As the desorbed substances, water, Cl, C_(x)H_(y)-basedimpurities, substances decomposed by these, and the like may be given.

In addition, in this temperature zone, namely, in the temperature zoneexceeding 450° C., even the C_(x)H_(y)-based impurities are desorbedfrom the SiOC film as shown in FIG. 12C. In addition, when the desorbedC_(x)H_(y)-based impurities pass through the SiOC film, re-adsorption ofC onto an adsorption site of the SiOC film may be caused by a reactionof the desorbed C_(x)H_(y)-based impurities with Cl. Namely, C derivedfrom the C_(x)H_(y)-based impurities is adsorbed onto any one element(atom) constituting the SiOC film, namely, the dangling bond of Si bythe reaction between the C_(x)H_(y)-impurities and Cl. The bond of C andSi formed in this manner is unstable and weak. Thus, C derived from theC_(x)H_(y)-impurities do not become a component constituting the SiOCfilm but remains in the SiOC film as impurities. When C is re-adsorbedonto the adsorption site of the SiOC film, there are cases in which Calone is re-absorbed onto the adsorption site, or in which C in the formof C_(x)H_(y) is re-adsorbed onto the adsorption site.

Namely, in this temperature zone, namely, in the temperature zoneexceeding 450° C., the film shrinking rate of the SiOC film is increasedby the above-described undesirable reaction, and the impurities cannotbe sufficiently desorbed and removed from the SiOC film. Consequently, adielectric constant (k value) of the SiOC film cannot be sufficientlyreduced.

By setting the temperature of the wafer 200 to be 300° C. or higher and450° C. or less, the impurities such as water or Cl may be sufficientlydesorbed and removed from the SiOC film while suppressing theabove-described undesirable reaction. Namely, when water, Cl, or thelike is desorbed from the SiOC film, oxidization of the SiOC film by thereaction of water and Cl may be suppressed, and an increase in the filmshrinking rate of the SiOC film may be suppressed. In addition,generation of HCl by the reaction of water and Cl may be suppressed andseparation of the Si—Cl bond or the Si—H bond of the SiOC film by HClmay be suppressed. Consequently, generation of the unnecessaryadsorption site of the SiOC film may be suppressed, thereby suppressingre-adsorption of desorbed substances onto the adsorption site. Inaddition, the reaction of C_(x)H_(y)-based impurities with Cl may besuppressed when the C_(x)H_(y)-based impurities are desorbed from theSiOC film, thereby suppressing re-adsorption of C onto the adsorptionsite of the SiOC film. In addition, as shown in FIG. 12C, when thetemperature of the wafer 200 is approximately 400° C., a desorptionamount of C_(x)H_(y)-based impurities becomes a peak. Therefore, bysetting the temperature of the wafer 200 to be 400° C. or less,preferably to be 350° C. or less, desorption of the C_(x)H_(y)-basedimpurities may be suppressed. Namely, a desorption amount of theC_(x)H_(y)-based impurities may be reduced. Thus, an absolute amount ofthe C_(x)H_(y)-based impurities desorbed from the SiOC film may bereduced, thereby further suppressing re-adsorption of C by the reactionof the C_(x)H_(y)-based impurities with Cl.

Namely, by adjusting the temperature of the wafer 200 to be theabove-described temperature zone, namely, 300° C. or higher and 450° C.or less, the film shrinking rate of the SiOC film may be reduced,re-absorption of desorbed substances including C or C_(x)H_(y) desorbedfrom the SiOC film onto the adsorption site of the SiOC film may besuppressed, and the impurities, particularly, impurities such as wateror Cl may be sufficiently desorbed and removed from the SiOC film.

In addition, by adjusting the temperature of the wafer 200 to be theabove-described temperature zone, namely, 300° C. or higher and 450° C.or less, the above-described impurities such as water or Cl may bedesorbed and removed from the SiOC film, and at least a part of theC_(x)H_(y)-based impurities may be desorbed and removed. In addition, atthis time, in such a temperature zone, reaction between theC_(x)H_(y)-based impurities desorbed from the SiOC film and Cl may besuppressed, thereby suppressing re-absorption of C onto the adsorptionsite of the SiOC film. Namely, by adjusting the temperature of the wafer200 to be such a temperature zone, C in the C_(x)H_(y)-based impuritiesdesorbed from the SiOC film once may be suppressed from beingre-absorbed onto the adsorption site of the SiOC film.

As described above, the temperature of the wafer 200 may be set to be atemperature in a range of 300° C. or higher and 450° C. or less,preferably, 300° C. or higher and 400° C. or less, more preferably, 300°C. or higher and 350° C. or less.

By performing the first heat treatment on the SiOC film under theabove-described condition, the above-described undesirable reaction maybe suppressed, and the impurities such as water or Cl of the SiOC filmmay be sufficiently desorbed and removed from the SiOC film. At least apart of the C_(x)H_(y)-based impurities may be desorbed and removed fromthe SiOC film while suppressing the above-described undesirablereaction. These impurities of the SiOC film are removed from the SiOCfilm, and therefore the SiOC film may be modified. Thus, etchingresistance of the SiOC film may be increased compared to the SiOC filmbefore performing the first heat treatment, and a dielectric constantthereof may be reduced to thereby improve a film quality (filmproperties) of the SiOC film.

However, in the step in which the first heat treatment is completed,namely, in the step in which the impurities such as water or Cl aresufficiently removed from the SiOC film, the C_(x)H_(y)-based impuritiesmay remain in the SiOC film. Namely, in such a temperature zone, theimpurities such as water or Cl or the C_(x)H_(y)-based impurities aredesorbed and removed from the SiOC film, but the impurities such aswater or Cl are previously removed prior to the C_(x)H_(y)-basedimpurities, and therefore in the step in which the most of theimpurities such as water or Cl is removed, the C_(x)H_(y)-basedimpurities may still remain in the SiOC film. Also, in this step, the kvalue of the SiOC film may not be sufficiently reduced due to theC_(x)H_(y)-based impurities remaining in the SiOC film. Thus, in thesecond heat treatment process to be described later, by heating the SiOCfilm at the second temperature equal to or higher than the firsttemperature, the C_(x)H_(y)-based impurities remaining in the SiOC filmmay be removed from the SiOC film on which heat treatment has beenperformed at the first temperature. Consequently, the k value of theSiOC film may be sufficiently reduced.

Second Heat Treatment

After the first heat treatment is completed, namely, after theimpurities such as water or Cl are sufficiently desorbed and removedfrom the SiOC film, the temperature of the wafer 200 is changed from thefirst temperature to the second temperature. The second temperature isset to be equal to or higher than the first temperature. Namely, thesecond temperature is set to be equal to or higher than the firsttemperature. An atmosphere in the processing chamber 201 is maintainedas the N₂ gas atmosphere having a desired pressure like the first heattreatment process.

When the temperature of the wafer 200 becomes the desirable temperaturenamely, the second temperature, this state is maintained for apredetermined time, and the second heat treatment is performed on theSiOC film on which the first heat treatment has been performed. Namely,the second heat treatment is performed at the second temperature on theSiOC film to which the first heat treatment has been performed at thefirst temperature.

At this time, the pressure inside the processing chamber 201 is set in arange of 133 to 101,325 Pa (1 to 760 Torr), preferably, 10,132 to101,325 Pa (76 to 760 Torr) by appropriately adjusting the APC valve244. A supply flow of the N₂ gas controlled by the MFCs 241 j to 241 lis set to be a flow rate in a range of 100 and 10,000 sccm. A timerequired for performing heat treatment with respect to the SiOC film onthe wafer 200 is set to be a time in a range of 1 and 120 minutes,preferably, 1 and 60 minutes, and more preferably, 1 to 30 minutes.

At this time, the temperature of the heater 207 is set such that thetemperature of the wafer 200 is the second temperature equal to orhigher than the first temperature in the above-described first heattreatment process. Specifically, the temperature of the wafer 200 is setto be a temperature equal to or higher than the first temperature, and atemperature in a range of 300° C. or higher and 900° C. or less,preferably, 350° C. or higher and 700° C. or less, more preferably, 400°C. or higher and 700° C. or less, and also preferably 450° C. or higherand 600° C. or less. Such a temperature range is determined afterconsidering that the C_(x)H_(y)-based impurities as the secondimpurities are efficiently and sufficiently desorbed and removed fromthe SiOC film, or considering a heat load or a thermal history which thewafer 200 receives.

As shown in FIG. 12C, when the temperature of the wafer 200 is below300° C., it is difficult to desorb and remove the C_(x)H_(y)-basedimpurities such as C₂H₂ from the SiOC film, whereby a modificationeffect of the SiOC film may be degraded. For example, when thetemperature of the wafer 200 is 200° C. or less, the C_(x)H_(y)-basedimpurities are hardly desorbed from the SiOC film. The C_(x)H_(y)-basedimpurities may be sufficiently desorbed from the SiOC film to be removedby setting the temperature of the wafer 200 to be 300° C. or higher.However, when the temperature of the wafer 200 is set to be 300° C., itmay take time for sufficiently desorb the C_(x)H_(y)-based impuritiesfrom the SiOC film. By setting the temperature of the wafer 200 to be350° C. or higher, a time during which the C_(x)H_(y)-based impuritiesare sufficiently desorbed from the SiOC film may be shortened. Inaddition, when the temperature of the wafer 200 is approximately 400°C., a desorption amount of the C_(x)H_(y)-based impurities becomes apeak. Thus, by setting the temperature of the wafer 200 to be 400° C. orhigher, desorption of the C_(x)H_(y)-based impurities may be promoted.Namely, the C_(x)H_(y)-based impurities may be efficiently desorbed fromthe SiOC film. In addition, a time until the C_(x)H_(y)-based impuritiesare sufficiently desorbed from the SiOC film may be further shortened.

Since the impurities such as water or Cl have been already removed fromthe SiOC film in the process of performing the second heat treatment,the above-described undesirable reaction may not occur. Namely, theundesirable reactions such as the oxidization of the SiOC film by thereaction between water and Cl, an increase in the film shrinking rate ofthe SiOC film caused by the oxidization, generation of HCl due to thereaction between water and Cl, separation of the Si—Cl bond or the Si—Hbond in the SiOC film due to HCl, generation of the unnecessaryadsorption site due to the separation, re-adsorption of the desorbedsubstances onto the adsorption site, re-adsorption of C onto theadsorption site due to the reaction between the C_(x)H_(y)-basedimpurities and Cl, and the like do not occur. This is because the secondtemperature includes the temperature zone (exceeding 450° C.) in whichthe undesirable reaction may occur, but substances for causingoccurrence of the undesirable reaction (water, Cl, or the like) are notgenerated when performing the second heat treatment. In addition, it isalso desirable to promote desorption of the C_(x)H_(y)-based impuritiesfrom the SiOC film by setting the temperature of the wafer 200 to be atemperature equal to higher than 450° C. The desorption of theC_(x)H_(y)-based impurities from the SiOC film may be promoted bysetting the temperature of the wafer 200 to be the temperature equal toor higher than 450° C. compared to when setting the temperature of thewafer 200 to be the temperature in a range of 300° C. and 350° C.

When the temperature of the wafer 200 exceeds 900° C., the heat load maybecome excessively large to affect electrical characteristics and thelike of a semiconductor device formed on the wafer 200. The effect onthe electrical characteristics and the like due to the heat load may besuppressed by setting the temperature of the wafer 200 to be atemperature equal to or less than 900° C. When the wafer 200 in whichthe SiOC film on which heat treatment is to be performed is formed issuitable for a memory device, the wafer may withstand heat atapproximately 900° C. In addition, even when the wafer 200 is suitablefor a logic device, the wafer may withstand heat at approximately 700°C. When setting the temperature of the wafer 200 to be a temperature of600° C. or less, thermal damages in a device structure and the like canbe more reliably avoided.

As described above, the temperature of the wafer 200 should be set to bea temperature in a range of 300° C. or higher and 900° C. or less,preferably 350° C. or higher and 700° C. or less, more preferably 400°C. or higher and 700° C. or less, and still more preferably 450° C. orhigher and 600° C. or less. Namely, the second temperature may be equalto or higher than the first temperature.

For example, when the first temperature is 300° C. or higher and 400° C.or less, and the second temperature is 450° C. or higher and 600° C. orless, the above-described undesirable reaction in each of the first heattreatment process and the second heat treatment process may be surelyprevented. Particularly, the undesirable reaction in the first heattreatment may be surely prevented by setting the first temperature to bea temperature in a range of 300° C. and 400° C. In addition, thesubstances (water, Cl, or the like) that cause occurrence of theundesirable reaction are not generated when performing the second heattreatment process by setting the second temperature to be a temperatureof 450° C. and 600° C., namely, even in the temperature zone in whichthe undesirable reaction may occur, thereby reliably preventingoccurrence of the undesirable reaction. In addition, the desorption ofthe C_(x)H_(y)-based impurities from the SiOC film may be more rapidlyperformed by setting the second temperature to be a temperature in arange of 450° C. and 600° C., namely, a temperature exceeding the firsttemperature.

In addition, the first temperature and the second temperature may be setto be the same temperature in a range of 400° C. and 450° C. When thefirst temperature and the second temperature are the same temperature ina range of 400° C. and 450° C., the undesirable reaction described inthe first heat treatment process and the second heat treatment processmay be surely prevented. In addition, when the first temperature and thesecond temperature are the same temperature, the temperature of thewafer 200 between the first heat treatment process and the second heattreatment process, namely, the temperature inside the processing chamber201 [temperature of the heater 207] may not need to be changed(adjusted). Namely, there is no need to wait till the temperature insidethe processing chamber 201 between the first heat treatment process andthe second heat treatment process becomes stable. Therefore, theseprocesses may be consecutively performed, and the temperature control ofthe heat treatment may be simplified.

By performing the second heat treatment on the SiOC film under theabove-described condition, the C_(x)H_(y)-based impurities in the SiOCfilm may be sufficiently desorbed and removed from the SiOC film whilesuppressing the undesirable reaction. As the impurities in the SiOC filmare removed from the SiOC film, the SiOC film is further modified, andtherefore etching resistance of the SiOC film may be further increasedthan the SiOC film on which the first heat treatment has been performedand the second heat treatment is not yet performed, and a dielectricconstant thereof may be further decreased. That is, the film quality(film property) of the SiOC film may be further improved. According totechniques of the present embodiment, the dielectric constant (k value)of the SiOC film may be decreased, for example up to about 2.7.

As described above, in the present embodiment of the present invention,the heat treatment is performed with respect to the SiOC film in thetemperature zone (first temperature zone) in which the undesirablereaction does not occur. Thus, the undesirable reaction does not occur,and the impurities (first impurities) such as water or Cl as substancesfor causing occurrence of the undesirable reaction are removed from theSiOC film. In addition, after the impurities (first impurities) such aswater or Cl as the substances for causing occurrence of the undesirablereaction are removed from the SiOC film, the heat treatment is performedwith respect to the SiOC film under the atmosphere in which theimpurities (first impurities) such as water or Cl as the substances forcausing occurrence of the undesirable reaction do not exist (generated)in the temperature zone (second temperature zone) including thetemperature zone in which the undesirable reaction may occur. Thus, theundesirable reaction does not occur, and the C_(x)H_(y)-based impurities(second impurities) are removed from the SiOC film on which the heattreatment has been performed in the first temperature zone (firsttemperature zone) in which the undesirable reaction does not occur.

The heat treatment in the present embodiment may referred to as two stepheat treatment (multi-step heat treatment). Also, the heat treatment maybe referred to as two step annealing (multi-step annealing), two stepmodification process (multi-step modification process), two stepimpurity removal process (multi-step impurity removal process), and thelike.

In the first heat treatment process and the second heat treatmentprocess, the inside of the processing chamber 201 is adjusted to be anoxygen-free atmosphere by the N₂ gas as the oxygen-free gas. Here, theoxygen-free atmosphere includes not only a state in which the oxidizinggas (O component) does not exist in the atmosphere inside the processingchamber 201 but also a state in which a concentration of the oxidizinggas (O concentration) in the atmosphere inside the processing chamber201 is decreased so as not to affect the SiOC film to be subjected totreatment. Thus, even when performing heat treatment at a temperaturehigher than the film formation temperature as above-described, the Oconcentration of the SiOC film may be prevented from being increasedexceeding the desirable concentration, namely, the SiOC film may beprevented from being excessively oxidized. In addition, since the insideof the processing chamber 201 is in the oxygen-free atmosphere, the Cconcentration of the SiOC film may be prevented from being decreasedbelow the desirable concentration in accordance with a progress ofoxidization and the like, namely, the desorption of C from the SiOC filmmay be suppressed. In this instance, the oxygen-free gas such as the N₂gas may act as the heat treatment gas. Also, the N₂ gas and the like mayact as a carrier gas for transporting the impurities desorbed from theSiOC film. Namely, the oxygen-free gas may act as an annealing gas forpromoting emission of these impurities from the SiOC film or from theinside of the processing chamber 201 to thereby promote modification ofthe SiOC film.

In order to set the inside of the processing chamber 201 as theoxygen-free atmosphere, the inside of the processing chamber 201 may bevacuum-exhausted using the exhaust system as the atmosphere generatingunit that generates the oxygen-free atmosphere, without supplying theoxygen-free gas such as the N₂ gas to the wafer 200.

Accordingly, most components including the O component may be exhaustedand removed from the atmosphere inside the processing chamber 201.However, exhaust of the O component remaining in the processing chamber201 is promoted by supplying the oxygen-free gas such as the N₂ gas tothe wafer 200 while exhausting the inside of the processing chamber 201,and therefore the inside of the processing chamber 201 may be easily setas the oxygen-free atmosphere. Also, by doing this, the oxygen-freeatmosphere inside the processing chamber 201 may be easily maintained bya dilution effect of the N₂ gas even when an out gas including the Ocomponent is generated from the inner wall of the processing vesselconstituting the processing chamber 201 or from the wafer 200 that isloaded from the outside.

The modification process of the SiOC film (annealing treatment) ismainly performed during the heat treatment in which the temperature ofthe wafer 200 is maintained stable at the desirable temperature.However, the modification process of the SiOC film may be performedwhile the temperature of the wafer 200 is maintained at the temperatureat which removal of the impurities in the SiOC film may be performedeven when raising the temperature of the wafer 200 in theabove-described process of adjusting the temperature of the wafer 200(the process of changing the temperature to the first temperature fromthe film formation temperature, the process of changing the temperatureto the second temperature from the first temperature, and the like) orwhen lowering the temperature of the wafer 200 in a purge process, whichwill be described later, of the inside of the processing chamber 201.Therefore, the process of modifying the SiOC film may be mainly referredto as a process of heating the SiOC film, but at least a partial periodof the process of adjusting the temperature of the wafer 200 and theprocess of purging the inside of the processing chamber 201 may beincluded in the process of modifying the SiOC film. In other words, theprocess of modifying the SiOC film may indicate a period from which thetemperature of the wafer 200 reaches a temperature required for themodification process up to immediately before the temperature of thewafer 200 reaches less than a temperature required for the modificationprocess. In addition, the process of modifying the SiOC film mayindicate a period ranging from which the temperature of the wafer 200reaches the temperature required for the modification process, namely,up to which the modification of the SiOC film is started and thencompleted.

As the oxygen-free gases, rare gases such as an Ar gas, a He gas, an Negas, an Xe gas, and the like may be used other than the N₂ gas.

Purge and Return to Atmospheric Pressure

When the process of modifying the SiOC film is completed, the N₂ gas issupplied into the processing chamber 201 from each of the gas supplypipes 232 j to 232 l in a state in which the valves 243 j to 243 l areopened, and exhausted from the exhaust pipe 231. The N₂ gas acts as thepurge gas, and thereby the inside of the processing chamber 201 ispurged so that gases remaining in the processing chamber 201, or gasesincluding substances such as the impurities desorbed from the SiOC filmare removed from the inside of the processing chamber 201. Next, theatmosphere inside the processing chamber 201 is substituted with theinert gas so that the pressure inside the processing chamber 201 isreturned to a normal pressure.

In addition, the power supply state to the heater 207 is adjusted or thepower supply to the heater 207 is stopped, and the temperature of thewafer 200 is lowered to a temperature less than 200° C., preferably,room temperature. The temperature of the wafer 200 may be lowered to apredetermined temperature in a short time using a cooling effect of thepurge gas by lowering the temperature of the wafer 200 in parallel withthe above-described purge and return to the atmospheric pressure.

Boat Unload and Wafer Discharge

After that, the seal cap 219 is lowered by the boat elevator 115 so thatthe lower end of the manifold 209 is opened, and the processed wafer 200is unloaded (boat unload) to the outside of the reaction tube 203 fromthe lower end of the manifold 209 in a state in which the processedwafer 200 is supported by the boat 217. The processed wafer 200 is takenout from the boat 217 (wafer discharge).

(3) Effect According to the Present Embodiment

According to the present embodiment, one or a plurality of effects shownas below may be obtained.

(a) Decomposition of the source such as the BTCSM gas may be promoted bysupplying the catalyst such as the pyridine gas together with a sourcecontaining Si, C, and a halogen element and having a Si—C bond such asthe BTCSM gas. Thus, the first layer may be formed even under the lowtemperature condition of 150° C. or less. In addition, when forming thefirst layer, formation of a chemical adsorption layer rather than aphysical adsorption layer of the source such as the BTCSM gas may beadvantageously performed and the formation rate of the first layer maybe increased.

In addition, decomposition of an oxidization agent such as the H₂O gasis promoted by supplying the catalyst such as the pyridine gas togetherwith the oxidization agent such as the H₂O gas, and therefore oxidizingpower of the oxidization agent such as the H₂O gas may be improved.Thereby, by an efficient reaction between the first layer and theoxidization agent such as the H₂O gas even under the low temperature of150° C. or less, the first layer may be modified to the second layer. Inaddition, a modification rate of the first layer may be increased.

That is, a film formation temperature of the SiOC film may be lowered bycatalysis of a catalyst such as the pyridine gas, and a film formationrate of the SiOC film may be increased.

(b) By using the gas acting as the source gas containing Si, C, and ahalogen element and having a Si—C bond such as the BTCSM gas, that is,the Si source and also acting as a C source, C may be added to the firstlayer. Consequently, a film to which C is added at a high concentration,that is, the SiOC film including a high C concentration may be formed.

The C concentration in the SiOC film may be increased by using thesource gas such as, particularly, the BTCSM gas including a Si—C—Si bondin which C is interposed between Si—Si without including a Si—Si bond.That is, C included in the source gas is bonded with Si at every two Cbonds. Thereby, when forming the first layer, bonds of C and Si includedin the BTCSM gas are all separated so that C may be suppressed from notbeing taken in the first layer. In addition, when modifying the firstlayer to the second layer, bonds of C and Si included in the first layerare all separated so that C may be suppressed from being desorbed fromthe first layer. That is, by using the source gas containing the Si—C—Sibond such as the BTCSM gas, the C concentration of the film can be moreincreased compared to when using the source gas without containing abond in which C is interposed between Si—Si such as the TCDMDS gas.

In addition, resistance (etching resistance) with respect tohydrofluoric acid (HF) of the SiOC film may be improved by adding C inthe film.

For reference, a wet etching rate (hereinafter, referred to as “WER”)with respect to HF of a 1% concentration (1% HF water solution) is about600 Å/min in the SiO film obtained using the catalyst gas under the lowtemperature condition, 200 Å/min in the SiO film obtained using theplasma under the low temperature condition, and 60 Å/min in a thermaloxidation film obtained by thermally oxidizing the silicon wafer withinan oxidation furnace. That is, the SiO film formed using the catalystgas or the plasma under the low temperature is likely to have etchingresistance lower than that of the thermal oxidation film. In order toimprove the etching resistance, adding of C to the film, that is,forming of the SiOC film is effective. When the film formationtemperature is 600° C. to 800° C., the SiOC film is formed bysimultaneously or alternately supplying the source gas (Si source) suchas the HCDS gas, the oxidizing gas such as the O₂ gas (O source), thecarbon-containing gas (C source) such as the propylene C₃H₆ gas, and thelike to the wafer 200. However, when the film formation is set at 150°C. or less, the SiOC film may be hardly formed using the above-describedgases or the above-described film formation techniques.

To solve this problem, for example, the SiOC film to which C is added ata high concentration, that is, the film having high etching resistancemay be formed even under the low temperature condition of 150° C. orless in the present embodiment. For example, the film having higheretching resistance compared to the thermal oxidation film may be formedin the present embodiment. In addition, the C concentration in the SiOCfilm, that is, the etching resistance may be highly accuratelycontrolled by properly adjusting the supply amount of the pyridine gasand the like.

(c) The film formation rate is improved and a robust film may be formedusing an alkylene halosilane source gas such as the BTCSM gas in whichthe molecular weight (molecular size) of an alkylene group included inone molecule is small. That is, when using the alkylene halosilanesource gas including the alkylene group such as a hexylene group, aheptylene group, or the like whose molecular weight is large in onemolecule, the alkylene group whose molecular weight is large causessteric hindrance that hinders the Si reaction in which the alkylenegroup whose molecular weight is large is included in the source gas, andtherefore the first layer formation may be hindered. In addition, whenthe above-described alkylene group remains in a state of not beingdecomposed or partially decomposed in the first layer, the alkylenegroup whose molecular weight is large causes steric hindrance thathinders the reaction between Si and H₂O gas in which the alkylene groupwhose molecular weight is large is included in the source gas, andtherefore the second layer formation may be hindered. To solve thisproblem, the above-described steric hindrance may not occur by using thealkylene halosilane source gas such as the BTCSM gas in which amolecular weight of the alkylene group included in one molecule issmall, and therefore the formation of each of the first layer and thesecond layer may be promoted. Consequently, the film formation rate maybe increased and the robust film may be formed. In addition, the sameeffect may be obtained even when using the alkyl halosilane source gassuch as the TCDMDS gas in which a molecular weight of the alkyl groupincluded in one molecule is small.

(d) The SiOC film may be adjusted to be a film in which the parts of Siincluded in the film are close each other by using the source gas suchas the BTCSM gas in which two parts of Si are included in one molecule.That is, when forming the first layer under a condition in which theBTCSM gas does not perform self-decomposition, the two parts of Siincluded in the BTCSM gas molecule are adsorbed onto the wafer 200(underlying film of the surface) while being mutually close. Inaddition, when forming the first layer under a condition in which theBTCSM gas performs self decomposition, the two parts of Si included inthe BTCSM gas molecule strongly tend to be accumulated onto the wafer200 while being close each other. That is, parts of Si included in thefirst layer may be adjusted to be close each other in comparison with acase using a gas in which only one Si is included within one moleculesuch as the tris(dimethylamino)silane (Si[N(CH₃)₂]₃H, abbreviated as3DMAS) gas by using the gas such as the BTCSM gas in which two parts ofSi are included in one molecule. Consequently, the SiOC film may beadjusted to the film in which the parts of Si included in the film aremutually close. Thereby, the etching resistance of the film may beimproved.

(e) As the supply of the source such as the BTCSM gas and the catalystsuch as the pyridine gas and the supply of the oxidation agent such asthe H₂O gas and the catalyst such as the pyridine gas are alternatelyperformed, these gases may be properly reacted under a condition inwhich the surface reaction is predominant. Consequently, step coverageof the SiOC film and controllability of the film thickness may berespectively improved. In addition, an excessive atmospheric reactionwithin the processing chamber 201 may be avoided, and thereforegeneration of the particles may be restricted.

(f) The first impurities (impurities such as water, Cl, or the like) maybe removed from the SiOC film by heating the SiOC film at the firsttemperature higher than the film formation temperature of the SiOC film.After that, The second impurities (C_(x)H_(y)-based impurities)different from the first impurities may be removed from the SiOC film onwhich the first heat treatment has been performed by heating the SiOCfilm at the second temperature higher than or equal to the firsttemperature. In result, the SiOC film may be adjusted to a film havingthe impurities less than that within the SiOC film in a state ofdeposition (as depo) before performing the process of modifying the SiOCfilm. Thereby, the etching resistance of the SiOC film is improved, andtherefore the dielectric constant may be lowered. That is, the filmquality of the SiOC film may be improved.

(g) A porous film may be formed by performing a series of treatments ofthe SiOC film formation process and the SiOC modification process. Thatis, the SiOC film may be adjusted to be a porous.

That is, at a least one Si—C bond and one Si—O bond exist within thefilm formed by the SiOC film formation process. A bond distance betweenSi and C is large than a bond distance between Si and O. Therefore, adistance between atoms becomes large in the SiOC film by introducing theSi—C bond to the film and the film density becomes sparse compared witha SiO₂ film. In addition, the Si—C—Si bond may exist in the SiOC film,and in this case, the film density becomes further sparse. Particularlywhen using the gas including the Si—C—Si bond such as the BTCSM gas asthe source gas, the Si—C—Si bond may be easily included in the SiOCfilm, and therefore the film density strongly tends to be sparse. Thatis, a micro hole (pore), that is, a micro space may be generated in aportion in which the film density becomes sparse. That is, the SiOC filmformed in the process of forming the SiOC film becomes a film of theporous shape in the deposition state, that is, in which atom densitywithin the film is low.

In addition, when the impurities such as water, Cl, or the like or theC_(x)H_(y)-based impurities are desorbed out of the SiOC film in theprocess of modifying the SiOC film, a micro hole (pore), that is, amicro space is generated in the portions from which the impurities areremoved. That is, the SiOC film modified by the process of modifying theSiOC film becomes the porus-shaped film in which the becoming of theporus is further progressed than the SiOC film in the deposition state,that is, a film in which the atom density within the film is furtherlow. However, when the above-described undesirable reaction occurs inthe process of modifying the SiOC film, the film contraction ratio ofthe SiOC film becomes large, and therefore the porous state of the SiOCfilm may be hardly maintained. Also, the modification (change) of theSiOC film may be performed in the state in which the becoming of theporous is progressed while maintaining the porous state in thedeposition state by performing the process of modifying the SiOC film inthe above-described treatment condition. That is, the film quality ofthe SiOC film may be improved.

(h) The dielectric constant (k value) of the SiOC film may be lower thana dielectric constant of the SiO₂ film by performing the series oftreatments of the process of forming the SiOC film and the process ofmodifying the SiOC film. That is, the SiOC film may enable to be theporus as described above by performing the series of treatments of theprocess of forming the SiOC film and the process of modifying the SiOCfilm. In addition, the impurities such as water, Cl, or the like or theC_(x)H_(y)-based impurities may be removed from the SiOC film byperforming the process of modifying the SiOC film. Since the impuritiessuch as water and the like have a permanent dipole moment, these arematerials that increase the dielectric constant by changing directionsalong an electric field. The dielectric constant of the SiOC film may belowered than the SiO₂ film by becoming the porous of the SiOC film andremoving the materials that increase the dielectric constant. Accordingto the film formation sequence in the first embodiment of the presentinvention, it is confirmed that the dielectric constant of the SiOC filmmay be lowered to, for example, 3.0 or less, particularly up to 2.68.

(i) In addition, the thin film such as, for example, a silicon carbonnitride (SiCN) film in which C is added to the silicon nitride (SiN)film or a silicon oxycarbon nitride (SiOCN) film in which O is added toa SiCN film, or the like may be used as the thin film satisfying thefilm formation at the low temperature, the low WER (high etchingresistance), the low dielectric constant, and the like in a transistor,a resistance memory (ReRAM), or a magnetic random access memory (MRAM)being developed as a next generation memory. Meanwhile, in order tofurther lower the dielectric constant by further improving the etchingresistance of these thin films, the C concentration or the Oconcentration within the film should be increased so as to lower the Nconcentration. However, it is hard to increase the C concentration andthe like while restricting the N concentration to a level of theconcentration, for example, less than the level of impurities in theabove-described method in which various gases are alternately suppliedso as to form the film and also in a low temperature region.

To solve this problem, in the first embodiment of the present invention,the C concentration within the thin film may be increased or controlledin an excellent accuracy by using the source gas including Si, C, and Clso as to include the Si—C bond even under the low temperature conditionof 150° C. or less.

(4) Modification Example of the First Embodiment of the PresentInvention

The sequence of the first embodiment of the present invention is notlimited to the embodiment shown in FIG. 4A, but may be changed as themodification examples shown bellow.

Modification Example 1

In the Step 1a supplying the source gas, the alkylene halosilane sourcegas of a kind different from the BTCSM gas such as, for example, theBTCSE gas may be supplied as the source gas. Also, the alkyl halosilanesource gas such as the TCDMDS gas may be supplied. FIG. 4B shows anexample using the TCDMDS gas instead of the BTCSM gas as the source gas.In this instance, the opening/closing control of the valve 243 d in Step1a is performed in the same sequence as the opening/closing control ofthe valve 243 a in Step 1a of the film formation sequence as shown inFIG. 4A. The other processing conditions or sequences are performed asthe same as the film formation sequence shown in, for example, FIG. 4A.

According to this modification example, the film formation sequence hasthe same effect as the film formation sequence shown in FIG. 4A.

In addition, the C concentration and the like may be controlled withinthe SiOC film by appropriately selecting kinds of the source gases likethe modification example 1. In addition, a Si concentration and an Oconcentration relative with respect to the C concentration may bechanged by controlling the C concentration within the SiOC film.

As this single factor, for example, disposition difference of the Cwithin the molecular structures of the respective source gases may begiven. That is, the BTCSM gas, the BTCSE gas, and the like are sourcegases including the Si—C—Si bond or the Si—C—C—Si bond, and havemolecular structures in which C is interposed between parts of Si. Aplurality of Cl parts bond with the remaining bonds without boding withC of four bonds of Si included in the BTCSM gas or the BTCSE gas. Forexample, Cl bonds with three bonds among the four bonds of Si in both ofthe BTCSM gas and the BTCSE gas. As such, the BTCSM gas, the BTCSE gas,or the like is considered to have high reactivity than the source gas inwhich the number of Cl included in the one molecule is small (forexample, four or less), because a plurality of Cl (for example, six) areincluded within one molecule in the BTCSM gas, the BTCSE gas, or thelike. The reaction occurring when forming the first layer may beefficiently performed by using the BTCSM gas, the BTCSE gas, or the likethat has high reactivity as the source gas, and therefore the filmformation rate of the SiOC film may be increased. In addition, a rangeof the treatment condition enabling the film formation to progress, thatis, a process window may be extended by using the source gas with thehigh reactivity. Since the film formation condition enabling a desirableC concentration to be obtained from within the broad process window maybe selected, as a result, it is easy to increase the C concentrationwithin the SiOC film. In addition, the controllability of the Cconcentration within the SiOC film may be improved. Here, the number ofC included in the BTCSM gas is smaller than, for example, those of theTCDMDS gas and the like. However, it is considered that the smallernumber of C may not act disadvantageously to improve the C concentrationin the SiOC film. According to the inventors of the present invention,it is confirmed that the C concentration is easily improved when usingthe BTCSM gas than when using the TCDMDS gas.

In addition, the TCDMDS gas, the DCTMDS gas, or the like is the sourcegas not including the Si—C—Si bond or the Si—C—C—Si bond, and has amolecular structure in which the alkyl group such as the methyl groupand the like bonds with Si, that is, a molecular structure in which apartial chloro group of the chlorosilane source gas is substituted withthe methyl group. The TCDMDS gas, the DCTMDS gas, or the like has thesmall number of Cl included in the one molecule (for example, four orless), it is considered that the reactivity thereof may be degraded thanthe source gas such as the BTCSM gas, the BTCSE gas, or the like.Thereby, the reaction is enabled to progress relatively slow whenforming the first layer by using the TCDMDS gas, the DCTMDS gas, or thelike as the source gas, and therefore, the SiOC film may be formed to adenser film. As a result, a high etching resistance may be maintainedeven when appropriately suppressing the C concentration in the SiOCfilm. In the comparison between the case in which the TCDMDS gas is usedas the source gas and the case in which the DCTMDS gas is used as thesource gas, it is confirmed that the DCTMDS gas including the methylgroup, that is, including a plurality of C within one molecule actsadvantageously to the blow-in amount of C into the film.

As such, the C concentration within the SiOC film may be easilyincreased by selecting to supply, for example, the BTCSM gas, the BTCSEgas, or the like as the source gas. In addition, the C concentrationwithin the SiOC film may be appropriately suppressed while maintainingthe etching resistance by selecting to supply, for example, the TCDMDSgas, the DCTMDS gas, or the like as the source gas as the source gas. Inthis manner, the C concentration within the SiOC film may be controlledin an excellent accuracy by selecting to supply a specific source gasfrom the plurality of source gases.

Modification Example 2

In Step 2 a supplying the O₂ gas, the amine-based catalyst gas whosemolecular structure is different from that of the pyridine gas, that is,the amine-based catalyst gas of a kind different from the pyridine gasmay be supplied as the catalyst gas. That is, the kind of the catalystgas supplied together with the source gas may be different from the kindof the catalyst gas supplied together with the oxidizing gas. In thisinstance, the amine-based catalyst gas of the kind different from thepyridine gas may be supplied from the gas supply pipe 232 c in Step 2A.The other treatment conditions or sequences are performed as the same asthe film formation sequence shown in, for example, FIG. 4A.

According to the modification example 2, the film formation sequence hasthe same effect as the film formation sequence shown in FIG. 4A.

In addition, the C concentration and the like may be controlled in theSiOC film by appropriately selecting kinds of the catalyst gases in thesame way as the modification example 2. In addition, a Si concentrationand an O concentration may be relatively changed by controlling the Cconcentration within the SiOC film.

As this single factor, for example, strength difference of the catalysisin accordance with the molecular structures of the catalyst gases may begiven. The decomposition of the oxidizing gas is promoted by selecting acatalyst gas with a large value of pKa, and therefore oxidizingproperties thereof may be increased. As a result, the Si—C bond includedin the first layer is cut in the Step 2 a, and the C concentrationwithin the SiOC film being finally formed may be lowered. In addition,the decomposition of the oxidizing gas is properly restricted byselecting the catalyst gas with a small value of Pka, and therefore theoxidizing properties thereof may be lowered. As a result, the Si—C bondincluded in the first layer becomes easy to be maintained in the Step2a, and therefore the C concentration within the SiOC film being finallyformed may be increased. In addition, as the other factors, vaporpressure difference between various substances involved in the catalysisof the catalyst gas, salt being generated, or the like may be given.

Modification Example 3

During performance of a cycle of the above-described Step 1a and Step 2aa plurality of times, kinds of the source gas or kinds of the catalystgas may be changed. Also, during performance of a cycle of theabove-described Step 1a and Step 2a a plurality of times, an amount ofthe catalyst gas may be changed.

In this instance, the change of the kinds of the source gas may beperformed only once or may be performed a plurality of times. Also, thekinds of the source gas being used may be two or three or more. Acombination of the source gases may be arbitrarily selected from thesource gases including Si, C, and the halogen element so as to includethe Si—C bond. The sequence using the source gases may be arbitrarilyselected. In addition, the change of the kinds of the catalyst gas maybe performed only once or a plurality of times. Also, the kinds of thecatalyst gas being used may be two or three or more. The combination orthe sequence of the catalyst gases may be arbitrarily selected. Inaddition, when changing a supply amount of the gas, the supply amountmay be changed to a large flow amount from a small flow amount or to asmall flow amount from a large flow amount. Also, the change of thesupply amount of the catalyst gas may be performed only once or aplurality of times. In this instance, the supply amount of the catalystgas may be changed increasingly or decreasingly in stage to a large flowamount from a small flow amount or to a small flow amount from a largeflow amount or may be properly changed up and down in an arbitrarycombination.

According to the modification example 3, the same effect as the filmformation sequence shown in FIG. 4A is obtained. In addition, accordingto the modification example 3, the concentration of C within the SiOCfilm may be changed in a film thickness direction. Also, the relativeconcentrations of Si and C within the film may be changed even in thefilm thickness direction by changing the concentration of C within theSiOC film in the film thickness direction. As a result, the etchingresistance, the dielectric constant, or the like of, for example, theSiOC film may be changed in the film thickness direction.

Modification Example 4

The present invention is not limited to the case using the substrateprocessing apparatus including each of the plurality of source gassupply lines and the plurality of catalyst gas supply lines as shown inFIG. 1, but a substrate processing apparatus including only a specificgas supply line of the plurality of gas supply lines shown in FIG. 1 maybe even used. However, when using the substrate processing apparatusincluding the plurality of gas supply lines, a specific gas may beeasily selected to be supplied from a plurality of kinds of gases inaccordance with a desirable film composition and the like byappropriately selecting the gas supply line being used. In addition, afilm having various composition ratios and film qualities may be formedto have a general purpose and also to have excellent reproducibility onone substrate processing apparatus. In addition, when adding orreplacing kinds of gases, the degree of freedom operating the apparatusmay be secured.

Modification Example 5

The process of forming the SiOC film and the process of modifying theSiOC film may be performed in different processing chambers.

For example, the process of forming the SiOC film is performed within aprocessing chamber 201 (hereinafter, referred to as a first processingchamber) included in the substrate processing apparatus (hereinafterreferred to as a first substrate processing unit) shown in FIG. 1.Operations of each unit composing the first substrate processing unitare controlled by a first control unit. A cycle including Step 1b andStep 2b likewise with the above-described Step 1 a and Step 2a isperformed a predetermined number of times using the first substrateprocessing unit. Then purge, return to the atmospheric pressure, boatunload, and the wafer discharge in the processing chamber 201 aresequentially executed. In succession, the process of heating the SiOCfilm formed on the wafer 200 taken out of the boat 217, that is, theprocess of modifying the SiOC film is performed in a processing chamberdifferent from the processing chamber 201. In this instance, forexample, a processing chamber (hereinafter, referred to as a secondprocessing chamber) included in a substrate processing apparatus(hereinafter referred to a second substrate processing unit) configuredlikewise with the substrate processing apparatus shown in FIG. 1 anddifferent from the apparatus performing the process of forming the SiOCfilm may be used. Operations of each unit composing the second substrateprocessing unit are controlled by a second control unit. The wafercharge and the boat load are sequentially executed using the secondsubstrate processing unit likewise with the performance of the processof forming the SiOC film in the first substrate processing unit. Also,the pressure adjustment and the temperature adjustment are performedlikewise with the above-described performance of the process ofmodifying the SiOC film. After that, the above-described first heattreatment, second heat treatment, purge, atmospheric pressure return,boat unload, and wafer discharge are sequentially executed likewise withthe above-described embodiment of the present invention. The treatmentcondition or the treatment sequence in the modification example 5 is setto the same as the film formation sequence shown in FIG. 4A.

As described above, the process of forming the SiOC film and the processof modifying the SiOC film may be performed even in different processingchambers (in Ex-Situ) (a first processing chamber and a secondprocessing chamber) as well as performed in the same processing chamber201 (in In-Situ). When performing both processes in in situ, thetreatment may be consistently performed in a state in which the wafer200 exists under the vacuum while not exposing the wafer 200 to theatmosphere during the performance, and therefore a stable film formationprocess may be performed. When performing the both processes in ex situ,the temperatures within respective processing chambers may be set totemperatures, for example, in each of the processes or close thereto inadvance, and the time for required for the temperature adjustment isshortened, and therefore production efficiency may be increased.

The substrate processing system is configured mainly with the firstsubstrate processing unit forming the SiOC film and the second substrateprocessing unit heating the SiOC film. However, the substrate processingsystem is not limited to the case in which the first substrateprocessing unit and the second substrate processing unit are configuredrespectively independent apparatus (stand alone type apparatus) groupsas described above, but may be configured as one apparatus in which thefirst substrate processing unit and the second substrate processing unitare mounted on the same platform. In addition, the apparatus performingthe process of modifying the SiOC film may be configured as an apparatuswith a configuration different from the substrate processing apparatusshown in FIG. 1, that is, as an annealing-dedicated processing system(heat treatment furnace) and the like.

Second Embodiment

Next, the second embodiment of the present invention will be describedwith reference to FIG. 6A. The substrate treatment apparatus shown inFIG. 1 and FIG. 2 is used in the second embodiment of the presentinvention as in the above-described first embodiment of the presentinvention. Operations of each of the units configuring the substratetreatment apparatus are controlled by the controller 121 in thedescription that follows.

In the film formation sequence according to the present embodiment, byexecuting, a specific number of times (n times), a cycle including aprocess of supplying the BTCSM gas as the source gas containing Si, C,and Cl and having the Si—C bond to the wafer 200; a process of supplyingthe O₃ gas as the oxidizing gas to the wafer 200; and a process ofsupplying the TEA gas as the catalyst gas to the wafer 200, the SiOCfilm as a thin film containing Si, O, and C may be formed on the wafer200.

At this time, the process of supplying the BTCSM gas is performed in astate in which the process of supplying the TEA gas is not performed,and the process of supplying the O₃ gas is performed in a state in whichthe process for supplying the TEA gas is performed.

In addition, after the SiOC film forming process is performed, theprocess of modifying the SiOC film may be performed in the same manneras in the above-described embodiment.

Hereinafter, differences between the SiOC film formation process of thepresent embodiment and the SiOC film forming process of theabove-described embodiment will be described in detail.

SiOC Film Forming Process

After wafer charging, boat loading, pressure adjustment, and temperatureadjustment, the following two Steps 1c and 2c are subsequentlyperformed.

Step 1c (BTCSM Gas Supply)

In the same sequence as in Step 1a of the film formation sequence shownin FIG. 4A, the BTCSM gas is supplied to the wafer 200. At this time,the valves 243 c and 243 i are closed, and supply of the BTCSM gas tothe wafer 200 is performed in a state in which supply of the amine-basedcatalyst gas such as the pyridine gas or the TEA gas is stopped. Thatis, when supply of the BTCSM gas to the wafer 200 is performed, supplyof the catalyst gas is not performed.

In addition, in order to prevent invasion of the BTCSM gas into thebuffer chamber 237 and the nozzles 249 b and 249 c, the valves 243 k and243 l are opened to flow the N₂ gas into the gas supply pipes 232 k and232 l. The N₂ gas is supplied into the processing chamber 201 throughthe gas supply pipes 232 b and 232 c, the nozzles 249 b and 249 c, andthe buffer chamber 237, and exhausted from the exhaust pipe 231.

At this time, by appropriately adjusting the APC valve 244, the pressureinside the processing chamber 201 is in a range of 1 to 13,330 Pa,preferably, 133 to 2,666 Pa. The supply flow rate of the BTCSM gascontrolled by the MFC 241 a is in a range of 1 to 2,000 sccm. The supplyflow rate of the N₂ gas controlled by each of the MFCs 241 j to 241 l isin a range of 100 to 10,000 sccm. The time required for supplying theBTCSM gas to the wafer 200, that is, a gas supply time (irradiationtime), is in a range of 1 to 100 seconds, preferably 5 to 60 seconds.

At this time, the temperature of the heater 207 is set to be atemperature in a range of room temperature or higher and 150° C. orless, preferably, room temperature or higher and 100° C. or less, andmore preferably, 50° C. or higher and 100° C. or less. In the case inwhich the catalyst gas is not supplied in the supply of the BTCSM gas,when the temperature of the wafer 200 is less than 250° C., the BTCSM isnot easily adsorbed onto the wafer 200, whereby a practical filmformation rate may not be obtained. In the present embodiment, in Step2a which is subsequently performed, this problem may be solved bycombining the O₃ gas and the TEA gas even when the temperature of thewafer 200 is less than 250° C. When the temperature of the wafer 200 is150° C. or less or 100° C. or less based on the assumption that Step 2 ais subsequently performed, an amount of heat applied to the wafer 200may be reduced, thereby satisfactorily performing control of a thermalhistory which the wafer 200 receives. In this instance, when thetemperature of the wafer 200 is room temperature or higher, a sufficientfilm formation rate may be obtained. Thus, the temperature of the wafer200 is set in a range of room temperature or higher and 150° C. or less,preferably, room temperature or higher and 100° C. or less, and morepreferably, 50° C. or higher and 100° C. or less.

By supplying the BTCSM gas to the wafer 200 under the above-describedcondition, the silicon-containing layer containing C and Cl with athickness of less than one atomic layer to several atomic layers as thefirst layer is formed on the wafers 200 (under layer of its surface).Under the low temperature condition of 150° C. or less as describedabove, an adsorption layer of the BTCSM gas, that is, a physicaladsorption layer of the BTCSM gas, may be mainly formed as the firstlayer by physical adsorption with insufficient thermal decomposition.

In this manner, when the first layer is mainly constituted of thephysical adsorption layer of the BTCSM gas, the first layer is noteasily mounted on the wafer 200. In addition, even when the oxidizationprocess is performed after that, the first layer is not easily changedto the SiOC layer including a strong bond. Namely, when the catalyst gasis not supplied in the supply of the BTCSM gas, the oxidizing reactionof the first layer is difficult to perform even when the catalyst gas issupplied in the following oxidization process. As a result, a filmformation rate of the SiOC film may be reduced, or formation of the SiOCfilm may be impossible.

In the above-described embodiment with respect to this problem, bysupplying the catalyst gas in both of the process of supplying thesource gas and the process of supplying the oxidizing gas, the mountingof the first layer on the wafer 200 may be promoted. As described above,the catalyst gas weakens the bonding power of the O—H bond on thesurface of the wafer 200 to promote a thermal decomposition reaction ofthe BTCSM gas, and therefore the formation of the first layer by theadsorption of the BTCSM gas molecules may be promoted, thereby securelymounting the first layer on the wafer 200.

In this regard, in the present embodiment, the catalyst gas may be usedonly in Step 2c which is subsequently performed. However, in the presentembodiment, by combining the oxidizing gas (for example, O₃ gas) havingstrong oxidizing power and the catalyst gas (for example, amine-basedcatalyst gas such as TEA gas) having strong catalysis in Step 2c, theabove-described problem may be solved. By using the combination of thesegases, the oxidization power of the oxidizing gas in Step 2c may besignificantly increased. Consequently, even when the first layer ismainly constituted of the physical adsorption layer of the BTCSM gas,the oxidizing reaction of the first layer is reliably performed to formthe SiOC layer including strong bonds. Namely, a bond with an underlayer or bonds between adjacent molecules or atoms of the layer may forma strong SiOC layer.

In addition, in the present embodiment, there is no need to pass througha complex reaction system using the catalyst gas at the time of supplyof at least the BTCSM gas, and therefore construction of the filmformation process may be facilitated. In addition, since the catalystgas is not supplied in the supply of the BTCSM gas, salts generated bythe catalysis are prevented from being a particle source, therebyimproving a quality of the film formation process. In addition, sincethe catalyst gas is not supplied in the supply of the BTCSM gas, anamount of use of the catalyst gas may be reduced when viewed from theentire film formation process, thereby reducing costs for film formationprocess.

Residual Gas Removal

Thereafter, in the same sequence as in the above-described embodiment,the supply of the BTCSM gas is stopped, and removal of the residual gasfrom the inside of the processing chamber 201 may be performed.

Step 2c (O₃ Gas+TEA Gas Supply)

When Step 1c is completed, O₃ gas and TEA gas flow into the processingchamber 201. In Step 2c, closing and opening control of the valves 243 gand 243 i is performed in the same sequence as the closing and openingcontrol of the valves 243 a and 243 c in Step 2a shown in FIG. 4A.

In this instance, the flow rate of the O₃ gas controlled by the MFC 241g is in a range of 1,000 to 10,000 sccm. The supply rate of the TEA gascontrolled by the MFC 241 i is set such that a ratio of the supply rate(sccm) of the O₃ gas and the supply rate (sccm) of TEA gas supply is,for example, in a range of 0.01 to 100, more preferably 0.05 to 10. Thesupply flow rate of the N₂ gas controlled by the MFCs 241 j to 241 l isin a range of 100 to 10,000 sccm. A time required for supplying the O₃gas and the TEA gas to the wafer 200, that is, a gas supply time(irradiation time), is in a range of 1 to 100 seconds, preferably 5 to60 seconds. The temperature of the heater 207 is set in the sametemperature zone as when supplying the BTCSM gas in Step 1c, forexample, in a rage of room temperature or higher and 150° C. or less,preferably room temperature or higher and 100° C. or less, and morepreferably 50° C. or higher and 100° C. or less. The other processingconditions are the same processing conditions as in Step 2a of the filmformation sequence shown in FIG. 4A.

The O₃ gas supplied into the processing chamber 291 is activated byheat, and exhausted from the exhaust pipe 231. Here, the activated O₃gas is supplied to the wafer 200. The gas flowing into the processingchamber 201 is the thermally activated O₃ gas, and the BTCSM gas doesnot flow in the processing chamber 201. Thus, the O₃ gas is supplied tothe wafer 200 in a state of being activated without causing a gas phasereaction, and reacts with at least a part of the first layer(silicon-containing layer containing C and Cl) formed on the wafer 200in Step 1c. Thus, the first layer is thermally oxidized into non-plasmato be changed to the second layer containing Si, O, and C, namely, theSiOC layer.

The TEA gas promotes decomposition of the O₃ gas to improve theoxidizing power of the O₃ gas, and acts as the catalyst gas forpromoting a reaction between the O₃ gas and the first layer. Inparticular, by combining the O₃ gas and the TEA gas, the oxidizing powerof the O₃ gas may be significantly improved to exceed a predicted rangefrom normal catalysis. As described above, when the thermaldecomposition of the BTCSM gas is not sufficient because the catalystgas is not supplied in the supply of the BTCSM gas, sufficientreactivity may not be obtained even when the catalyst gas is supplied inthe supply process of the oxidizing gas thereafter. However, bysimultaneously supplying the O₃ gas and the TEA gas, the oxidizingreaction between the O₃ gas and the first layer may be appropriatelyperformed even when the adsorption layer of the BTCSM gas, that is, thephysical adsorption layer of the BTCSM gas, is mainly formed as thefirst layer by physical adsorption in which thermal decomposition inStep 1c is insufficient. That is, the oxidizing power of the O₃ gas maybe significantly increased due to the action of the TEA GAS, whereby theoxidizing process on the physical adsorption layer of the BTCSM gas maybe reliably performed. Consequently, a bond with an under layer or bondsbetween adjacent molecules or atoms may form a strong SiOC layer.

Residual Gas Removal

Thereafter, the valve 243 g is closed and the supply of the O₃ gas isstopped. In addition, the valve 243 i is closed and the supply of theTEA GAS is stopped. Removal of the residual gas from the inside of theprocessing chamber 201 may be performed in the same sequence as in theabove-described embodiment.

Execution Specific Number of Times

The above-described Steps 1c and 2c are set as one cycle, and byexecuting this cycle at least once, namely, a specific number of times(n times), a specific composition and a SiOC film with a specific filmthickness may be formed on the wafer 200. The fact that theabove-described cycle is preferably repeated multiple numbers of timesis the same as in the above-described embodiment.

SiOC Film Modifying Process

In the present embodiment, impurities such as water or Cl orC_(x)H_(y)-based impurities may be largely mixed in the SiOC film formedunder the low temperature condition. Pressure adjustment, temperatureadjustment, the first heat treatment, the second heat treatment, purgeand return to atmospheric pressure may be performed in the same sequenceand processing conditions as in the above-described embodiment to removethe impurities of the SiOC film, thereby modifying the SiOC film. Thus,the SiOC film having higher etching resistance and a lower dielectricconstant may be obtained compared to the SiOC film before performing themodifying process of the SiOC film.

Thereafter, boat unload and wafer discharge may be performed in the samesequence as in the above-described embodiment to complete the filmformation process of the present embodiment.

(2) Effects of the Present Embodiment

According to the present embodiment, one or a plurality of the effectswhich will be shown below as well as the same effects as theabove-described embodiment may be obtained.

(a) The supply of the BTCSM gas is performed on the wafer 200 in a statein which the supply of the catalyst gas to the wafer 200 is stopped.Thus, the film formation process may be simplified. In addition, saltsgenerated when supplying the catalyst gas in the supply of the BTCSM gasare not generated, and thus generation of particles is suppressed. Inaddition, an amount of use of the catalyst gas may be suppressed whenviewed from the entire film formation process, thereby reducingmanufacturing costs.

(b) The supply of the O₃ gas to the wafer 200 is performed on the wafer200 in a state in which the supply of the TEA gas is performed. Thus,the oxidizing power of the O₃ gas may be significantly increased. Bycombining the O₃ gas and the amine-based catalyst gas, the oxidizingpower of the O₃ gas may be significantly increased to exceed a predictedrange from normal catalysis. Thus, sufficient reactivity may be obtainedwith respect to the first layer even when the catalyst gas is notsupplied in the supply of the BTCSM gas, and the oxidizing reactionbetween the O₃ gas and the first layer may be appropriately performed.In addition, the rate of the oxidizing reaction may be improved tomaintain the film formation rate of the SiOC film.

As the amine-based gas which is combined with the O₃ gas, the TEA gas ismost preferable, a pyridine gas is the next most preferable, and apiperidine gas is the next most preferable. This is because atemperature range in which the SiOC film can be formed is widest in thecase of using the TEA gas as the catalyst gas, and is also wide in thecase of using the pyridine gas and the case of using the piperidine gas.

(c) According to the present embodiment, the same effect as theabove-described embodiment using FIG. 4A and the like may be obtained.However, the various effects provided in the above-described embodimentmay become more remarkable in the above-described embodiment than in thepresent embodiment. For example, an effect of reducing the dielectricconstant of the SiOC film may become more remarkable in theabove-described embodiment using the H₂O gas and the pyridine gas thanin the present embodiment using the O₃ gas and the TEA gas. This isbecause a degree of porosity of the SiOC film is increased when usingthe H₂O gas as the oxidizing gas compared to when using the O₃ gas asthe oxidizing gas. The SiOC film containing more water is formed whenusing the H₂O gas as the oxidizing gas than when using the O₃ gas as theoxidizing gas. By performing the first heat treatment and the secondheat treatment on the SiOC film containing more water, a larger numberof minute pores, that is, minute spaces, are generated, and thus theSiOC film may be more porous.

(3) Modification Example of the Present Embodiment

The film formation sequence of the present embodiment is not limited tothe embodiment shown in FIG. 6A, and the SiO film may be formed on thewafer 200 by changing the film formation sequence such as in themodification example shown in FIGS. 6B and 6C.

In this case, an HCDS gas or a BDEAS gas is used as the source gasrather than the BTCSM gas. In Step 1c of supplying the HCDS gas or theBDEAS gas, the opening and closing control of the valve 243 e or 243 fis performed in the same sequence as in the opening and closing controlof the valve 243 a in Step 1c. The supply flow of the HCDS gas or theBDEAS gas may be the same as the supply flow of the BTCSM gas in Step 1cof the film formation sequence shown in FIG. 6A. The other processingconditions are the same processing conditions as in Step 1c of the filmformation sequence shown in FIG. 6A.

Impurities such as moisture are likely to be included in the SiO filmformed under the low temperature condition in this manner. When usingthe HCDS gas as the source gas, impurities such as Cl are likely to beincluded in the SiO film. When using the BDEAS gas as the source gas,impurities such as C, H, or N are likely to be included in the SiO film.In the same sequence and processing conditions as the above-describedembodiment, the first heat treatment and the second heat treatment maybe performed on the SiO film to remove the impurities of the SiO film sothat the SiO film may be modified, and therefore the SiO film havinghigher etching resistance and a lower dielectric constant may beobtained compared to the SiO film on which the process of modifying theSiO film is not performed.

Third Embodiment

Next, the third embodiment of the present invention will be describedwith reference to FIGS. 7A and 7B. In the present embodiment, thesubstrate processing apparatus shown in FIGS. 1 and 2 is used in thesame manner as in the above-described embodiments. Operations ofrespective units constituting the substrate processing apparatus may becontrolled by the controller 121.

In the film formation sequences of the present embodiment, a process offorming a laminated film of the SiO film and the SiOC film on the wafer200 is performed by executing, a specific number of times (n times), acycle including: in a state in which a process of supplying the HCDS gasas the source gas containing Si and Cl to the wafer 200 is performed,performing the film formation sequence in a state in which a process ofsupplying the pyridine gas as the catalyst gas to the wafer 200 isperformed (Step 1d), and in a state in which a process of supplying theH₂O gas as the oxidizing gas to the wafer 200 is performed, performingthe film formation sequence in a state in which a process of supplyingthe pyridine gas as the catalyst gas to the wafer 200 is performed (Step2d), a process of forming the SiO film as a first thin film containingSi and O by executing a set including these processes a specific numberof times (m₁ times); and, in a state in which a process of supplying theBTCSM gas as the source gas containing Si, C, and Cl and having Si—Cbond to the wafer 200 is performed, performing the film formationsequence in a state in which a process of supplying the pyridine gas asthe catalyst gas to the wafer 200 is performed (Step 1e), performing thefilm formation sequence in a state in which a process of supplying theH₂O as the oxidizing gas to the wafer 200 is performed (Step 2e), and aprocess of forming the SiOC film as a second thin film containing Si, O,and C by executing a set including these processes a specific number oftimes (m₂ times).

In addition, after forming the laminated film of the SiO film and theSiOC film, a process of modifying the laminated film may be performed inthe same manner as in the above-described embodiments.

Hereinafter, differences between the process of the forming the SiO filmand the SiOC film of the present embodiment and those in theabove-described embodiments will be described in detail.

SiO Film Forming Process

The following two Steps 1d and 2d are sequentially performed after wafercharging, boat loading, pressure adjustment, and temperature adjustment.

Step 1d (HCDS Gas+Pyridine Gas Supply)

The HCDS gas is supplied to the wafer 200 in the same sequence as inStep 1c of the film formation sequence shown in FIG. 6B. In addition,the pyridine gas is supplied to the wafer 200 in the same sequence as inStep 1a of the film formation sequence shown in FIG. 4A. The processingconditions at this time are the same as in Step 1a of the film formationsequence shown in FIG. 6B and in Step 1a of the film formation sequenceshown in FIG. 4A. With respect to the HCDS gas, the pyridine gas showsthe same catalysis as the catalysis with respect to the BTCSM gas.

Thus, the silicon-containing layer containing Cl with a thickness ofless than one atomic layer to several atomic layers is formed on thewafers 200 as a first layer. By simultaneously flowing the HCDS gas andthe pyridine gas, the silicon-containing layer containing Cl may beformed on the wafer 200 under a relatively low temperature condition,for example, 150° C. or less.

Residual Gas Removal

Thereafter, the supply of the pyridine gas and the HCDS gas is stopped,and removal of the residual gas from the processing chamber 201 isperformed in the same sequence as in the above-described embodiments.

Step 2 d (H₇O Gas+Pyridine Gas Supply)

After Step 1d is completed and the residual gas inside the processingchamber 201 is removed, the H₂O gas and the pyridine gas are supplied tothe wafer 200 in the same supply sequence as in Step 2a of the filmformation sequence shown in FIG. 4A. The processing conditions at thistime are the same processing conditions as in Step 2a of the filmformation sequence shown in FIG. 4A. Thus, the first layer is thermallyoxidized into non-plasma to be changed to the second layer containing Siand O, namely, a silicon oxidizing layer (SiO layer).

Residual Gas Removal

Thereafter, the supply of the pyridine gas and the H₂O gas is stopped,and removal of the residual gas from the processing chamber 201 isperformed in the same sequence as in the above-described embodiments.

Execution Specific Number of Times

By setting the above-described Steps 1d and 2d as one set and executingthis set at least once, namely, a specific number of times (m₁ times),the SiO film having a predetermined composition and a predetermined filmthickness may be formed on the wafer 200. The fact that this set ispreferably repeated multiple numbers of times is the same as in theabove-described embodiments.

SiOC Film Forming Process

Next, Steps 1e and 2e are sequentially performed in the same sequence asin Steps 1a and 2 a of the film formation sequence shown in FIG. 4A. Bysetting Steps 1e and 2e as one set and executing this set at least once,namely, a specific number of times (m₂ times), the SiOC film having apredetermined composition and a predetermined film thickness may beformed on the SiO film. The fact that this set is preferably repeatedmultiple numbers of times is the same as in the above-describedembodiments.

Execution Specific Number of Times

By setting the above-described SiO film forming process and SiOC filmforming process as one cycle and executing this cycle at least once,namely, a specific number of times (n times), a laminated film of theSiOC film and the SiOC film may be formed on the wafer 200. In addition,any one of the SiO film forming process and the SiOC film formingprocess may be started first.

As shown in FIG. 7A, by executing the cycle including the SiO filmforming process and the SiOC film forming process once, the laminatedfilm (stacked film) obtained in such a manner that one SiO film and oneSiOC film are alternately laminated may be formed.

In addition, as shown in FIG. 7B, by executing the cycle including theSiO film forming process and the SiOC film forming process multiplenumbers of times, a laminated film (laminated film) obtained in such amanner that a plurality of SiO films and a plurality of SiOC films arealternately laminated may be formed. FIG. 7B illustrates an example inwhich the cycle including the SiO film forming process and the SiOC filmforming process are repeated twice.

Process of Modifying Laminated Film

In the present embodiment, impurities such as water or Cl orC_(x)H_(y)-based impurities may be largely mixed in the SiO film and theSiOC film formed under the low temperature condition. Pressureadjustment, temperature adjustment, the first heat treatment, the secondheat treatment, purge and return to atmospheric pressure may beperformed in the same sequence and processing conditions as in theabove-described embodiments to remove the impurities of the laminatedfilm, thereby modifying the laminated film. Thus, the laminated filmhaving higher etching resistance and a lower dielectric constant may beobtained compared to the laminated film before performing the modifyingprocess of the laminated film.

Thereafter, boat unloading and wafer discharge are performed in the samesequences as in the above-described embodiments to complete the filmformation process of the present embodiment.

Also in the present embodiment, the same effects as the above-describedembodiments may be obtained.

In addition, by controlling a film thickness ratio between the SiO filmand the SiOC film, for example, by controlling a ratio of the number oftimes (m₁, m₂) of the above-described respective sets, a compositionratio of the laminated film which is ultimately formed may be preciselycontrolled. In addition, in the film formation sequence shown in FIG.7B, the film thickness of each of the SiO film and the SiOC film is 5 nmor less, preferably 1 nm or less, and therefore the ultimately formedlaminated film may be provided as a layer having matchingcharacteristics in the laminated direction, namely, a nano-laminatedfilm having inseparable characteristics throughout the film. Inaddition, by setting the number of times (m₁ times and m₂ times) ofexecution of the above-described set to about one to ten times, the filmthickness of each of the SiO film and the SiOC film is 5 nm or less,preferably 1 nm or less.

(2) Modification Example of the Present Embodiment

The film formation sequence of the present invention is not limited tothe embodiments shown in FIGS. 7A and 7B, and may be changed to amodification example shown in FIGS. 8A and 8B. That is, in the SiO filmforming process, the supply of the catalyst gas may not be performed. Inaddition, in the SiO film forming process, the BDEAS gas containing Si,C, and N and having Si—N bonds may be used without using the HCDS gas asthe source gas. In addition, in the SiO film forming process, the O₂ gasactivated by plasma as the oxidizing gas, namely, the O₂ gas excitedinto a plasma state may be used.

In Step 1f of supplying the BDEAS gas, the opening and closing controlof the valve 243 f is performed in the same sequence as the opening andclosing control of the valve 243 e in Step 1d. At this time, the valves243 c and 243 i are closed, and the supply of the BDEAS gas to the wafer200 is performed in a state in which the supply of the amine-basedcatalyst gas such as the pyridine gas or the TEA gas is stopped. Thesupply flow of the BDEAS gas is the same as the supply flow of the HCDSgas in Step 1d of the film formation sequence shown in FIGS. 7A and 7B.The other processing conditions are the same as in Step 1d of the filmformation sequence shown in FIGS. 7A and 7B.

By supplying the BDEAS gas to the wafer 200, the silicon-containinglayer containing N and C with a thickness of less than one atomic layerto several atomic layers as the first layer is formed on the wafers 200(an under layer of its surface). The BDEAS gas is easily adsorbed ontothe wafer 200 or the like, and has high decomposition properties andreactivity. Thus, the first layer may be formed on the wafer 200 evenunder a relatively low temperature condition of 150° C. or less.

In Step 2f of supplying the O₂ gas activated by plasma, the opening andclosing control of the valve 243 h is performed in the same sequence asthe opening and closing control of the valve 243 b in Step 2d of thefilm formation sequence shown in FIGS. 7A and 7B. At this time, thevalves 243 c and 243 i are closed, and the supply of the O₂ gas to thewafer 200 is performed in a state in which the amine-based catalyst gassuch as the supply of the pyridine gas or the TEA gas is stopped. Thesupply flow rate of the O₂ gas controlled by the MFC 241 h is in a rangeof 100 to 10,000 sccm. A high frequency power applied between the rodelectrodes 269 and 270 is in a range of 50 to 1,000 W. The pressureinside the processing chamber 201 is in a range of 1 to 100 Pa. By usingplasma, the O₂ gas may be activated even when the pressure inside theprocessing chamber 201 is set to a relatively low pressure zone. A timerequired for supplying activated species obtained by plasma-exciting theO₂ gas to the wafer 200, namely, a gas supply time (irradiation time),is in a range of 1 to 100 seconds, preferably 5 to 60 seconds. The otherprocessing conditions are the same as in Step 2e of the film formationsequence shown in FIGS. 7A and 7B.

By supplying the O₂ gas activated by plasma to the wafer 200, anoxidizing process is performed on the first layer (silicon-containinglayer containing N and C) formed on the wafer 200. The first layer maybe changed to the second layer containing Si and O, namely, the SiOlayer.

According to the present modification example, the same effects as inthe film formation sequence shown in FIGS. 7A and 7B may be obtained.

Other Embodiments

The embodiments of the present invention have been described in detailabove. However, the present invention is not limited to theabove-described embodiments or modification examples, and variousmodifications may be made without departing from the spirit of thepresent invention.

The temperature control sequence of the heat treatment process of thepresent invention, that is, the annealing sequence, is not limited tothe above-described embodiments, and various modifications thereof maybe made as shown in FIGS. 14A through 14D and 15. FIG. 14A illustratesan annealing sequence in a case in which the second temperature ishigher than the first temperature in the same manner as in theabove-described embodiments. FIGS. 14B to 14D illustrate modificationexamples thereof. FIG. 15 illustrates an annealing sequence in a case inwhich the second temperature is a temperature equal to the firsttemperature. A horizontal axis of each of these drawings indicates anelapsed time (minutes), and a vertical axis thereof indicates a wafertemperature (° C.).

In the annealing sequence shown in FIG. 14A, by raising the temperatureof the wafer 200 after film formation up to the first temperature, andby maintaining the temperature of the wafer 200 constant for apredetermined time at the first temperature, the first heat treatment isperformed. Thereafter, by raising the temperature of the wafer 200 up tothe second temperature higher than the first temperature, and bymaintaining the temperature of the wafer 200 constant for apredetermined time at the second temperature, the second heat treatmentis performed. Thereafter, the temperature of the wafer 200 is lowered toa temperature at which unloading is possible.

According to the annealing sequence, by maintaining the temperature ofthe wafer 200 constant for a predetermined time at the first temperaturelower than the second temperature in the first heat treatment process,the above-described undesirable reaction may be reliably prevented. Inaddition, by sufficiently securing the time required for maintaining thetemperature of the wafer 200 at the first temperature, desorption of thefirst impurities (water or Cl) from the SiOC film may be reliablyperformed.

Thereafter, by maintaining the temperature of the wafer 200 constant fora predetermined time at the second temperature higher than the firsttemperature in the second heat treatment, desorption of the secondimpurities (C_(x)H_(y)-based impurities) in the second heat treatmentprocess may be rapidly performed. In addition, at this time, substances(water or Cl) that cause undesired reactions are not generated, andtherefore the above-described undesirable reaction may be reliablysuppressed. In addition, by sufficiently securing the time required formaintaining the temperature of the wafer 200 at the second temperature,desorption of the second impurities from the SiOC film may be reliablyperformed.

In the annealing sequence shown in FIG. 14B, the temperature of thewafer 200 after the film formation is raised up to the firsttemperature, and then the temperature of the wafer 200 is raised up tothe second temperature without maintaining the temperature of the wafer200 constant. Next, when the temperature of the wafer 200 reaches thesecond temperature, the temperature of the wafer 200 is lowered withoutmaintaining the temperature of the wafer 200 constant. In the annealingsequence, the first heat treatment process is performed between periodswhile the temperature of the wafer 200 reaches a temperature(temperature close to the first temperature) at which desorption of thefirst impurities from the SiOC film is started and while the desorptionof the first impurities from the SiOC film is completed. In addition,the second heat treatment process is performed within a period from whenthe temperature of the wafer 200 reaches a temperature (temperatureclose to the second temperature) at which desorption of the secondimpurities from the SiOC film is activated until the desorption of thesecond impurities from the SiOC film is completed. In addition,desorption of the first impurities from the SiOC film is completed tosome extent, that is, a ratio occupied by the second impurities amongthe impurities desorbed from the film is dominant, and a period untildesorption of the second impurities from the film is activated may beincluded in the second heat treatment process.

According to the annealing sequence, by appropriately adjusting amagnitude of each of a temperature raising rate or a temperaturelowering rate of the wafer 200, the first heat treatment process and thesecond heat treatment process are appropriately performed in the statedorder.

By lowering a magnitude of at least any one of a temperature raisingrate until the temperature of the wafer 200 reaches the firsttemperature and a temperature raising rate until the temperature of thewafer 200 reaches the second temperature exceeding the firsttemperature, the above-described undesirable reaction may be reliablyprevented in the first heat treatment process. Thus, desorption of thefirst impurities from the SiOC film may be reliably performed. By makingone of the temperature raising rate until the temperature of the wafer200 reaches the first temperature and the temperature raising rate untilthe temperature of the wafer 200 reaches the second temperatureexceeding the first temperature smaller than the other one, an executiontime of the first heat treatment process may be sufficiently secured,whereby desorption of the first impurities from the SiOC film may bereliably performed.

In addition, by lowering a magnitude of at least one of a temperatureraising rate until the temperature of the wafer 200 reaches the secondtemperature exceeding the first temperature and a temperature raisingrate after the temperature of the wafer 200 reaches the secondtemperature, an execution time of the second heat treatment process maybe sufficiently secured, whereby desorption of the second impuritiesfrom the SiOC film may be reliably performed. In addition, since thesubstances that cause undesirable reactions are not generated, theabove-described undesirable reactions may be reliably prevented. Forexample, by making one of the temperature raising rate until thetemperature of the wafer 200 reaches the second temperature exceedingthe first temperature and the temperature raising rate after thetemperature of the wafer 200 reaches the second temperature smaller thanthe other one, an execution time of the second heat treatment processmay be sufficiently secured, whereby desorption of the second impuritiesfrom the SiOC film may be reliably performed. In addition, a totalrequired time may be shortened.

According to the annealing sequence, since control of maintaining thetemperature of the wafer 200 constant is not performed, the temperaturecontrol may be simplified. For example, when the temperature of thewafer 200 immediately after the film formation is raised up to thesecond temperature, the temperature raising rate should be sufficientlylowered, and therefore the first heat treatment process and the secondheat treatment process are appropriately performed in the stated order.

The annealing sequence shown in FIGS. 14C and 14D is obtained bycombining the annealing sequences shown in FIGS. 14A and 14B. In theannealing sequence shown in FIG. 14C, the temperature of the wafer 200is continuously raised until reaching the second temperature, and whenthe temperature of the wafer 200 reaches the second temperature, thetemperature is maintained constant for a predetermined time and thenlowered. In addition, in the annealing sequence shown in FIG. 14D, whenthe temperature of the wafer 200 reaches the first temperature, thetemperature is maintained constant for a predetermined time and then israised up to the second temperature. Next, when the temperature of thewafer 200 reaches the second temperature, the temperature may be loweredwithout being maintained constant. These annealing sequences also havethe same effects as the annealing sequences shown in FIGS. 14A and 14B.In addition, an appropriate combination of the annealing sequences shownin FIGS. 14A through 14D may be used.

The annealing sequence shown in FIG. 15 is an example in which thesecond temperature is set to be equal to the first temperature. In thisannealing sequence, the temperature of the wafer 200 after filmformation is raised up to the first temperature, and then the raisedtemperature is maintained constant for a predetermined time before beinglowered.

When the temperature of the wafer 200 is raised up to the firsttemperature as described above, desorption of the first and secondimpurities from the SiOC film is started. At this time, desorption ofthe first impurities is completed earlier than desorption of the secondimpurities. In this annealing sequence, the first heat treatment processis performed within a period from when the temperature of the wafer 200reaches a temperature (temperature close to the first temperature) atwhich desorption of impurities from the SiOC film is started untildesorption of the first impurities from the SiOC film is completed. Inaddition, desorption of the first impurities from the SiOC film iscompleted to some extent, that is, a ratio occupied by the secondimpurities among the impurities desorbed from the film is dominant, andthe second heat treatment process is performed during a period untildesorption of the second impurities from the film is completed. Inaddition, the period from when desorption of the second impurities fromthe SiOC film is started until desorption of the first impurities fromthe SiOC film is completed may be included in the second heat treatmentprocess. That is, the first and second heat treatment processes aresimultaneously started, so that the first heat treatment process may befirst completed, and then the second heat treatment process may becompleted. Since the first temperature does not include the temperaturezone in which the above-described undesirable reaction occurs even whenthe first and second heat treatment processes are simultaneouslystarted, the above-described undesirable reaction may not occur when thefirst and second heat treatment processes are simultaneously performed.

According to this annealing sequence, by sufficiently securing the timerequired for maintaining the temperature of the wafer 200 at the firsttemperature, the first and second heat treatment processes may beappropriately performed. That is, by sufficiently securing the timerequired for maintaining the temperature of the wafer 200 at the firsttemperature after the first heat treatment process is completed, thesecond heat treatment process may be reliably performed without furtherraising the temperature of the wafer 200.

In addition, according to this annealing sequence, since the secondtemperature is set to be equal to the first temperature, that is, sincethe temperature of the wafer 200 is not raised up to a temperatureexceeding the first temperature, control of a thermal history which thewafer 200 receives may be satisfactorily performed. In addition,according to this annealing sequence, there is no need to raise thetemperature of the wafer 200 up to the temperature exceeding the firsttemperature, and therefore the heater 207 having a relatively smalloutput may be used, thereby reducing manufacturing costs of thesubstrate processing apparatus.

In addition, according to this annealing sequence, control of raisingthe temperature of the wafer 200 to a second stage is not performed, andtherefore the temperature control may be simplified. For example, bymaking sure that the temperature of the wafer 200 immediately after filmformation is raised up to the first temperature and then the timerequired for maintaining the temperature constant is sufficientlysecured, each of the first and second heat treatment processes may beappropriately performed.

In the above-described embodiments, an example in which the inert gas,the purge gas, and the oxygen-free gas are all supplied from the samegas supply system has been described. The present invention is notlimited thereto, and a part or all of an inert gas supply system, apurge gas supply system, and an oxygen-free gas supply system may beinstalled as a separate gas supply system. However, when the oxygen-freeatmosphere is generated in the processing chamber 201 only by theexhaust system, the oxygen-free gas supply system need not be installed.

In addition, in the above-described embodiments, when changing thesilicon-containing layer to the SiOC layer or the SiO layer, an exampleof using the oxidizing gas activated by heat together with the catalystgas, that is, an example of supplying the catalyst gas and the oxidizinggas under a plasma atmosphere (under the condition) has been described.The present invention is not limited thereto, and the oxidizing gasexcited by plasma together with the catalyst gas may be used. That is,the catalyst gas and the oxidizing gas may be supplied under theatmosphere (under the condition) of plasma. The processing conditions atthis time may be the same processing conditions in the above-describedembodiments or modification examples.

In addition, in the above-described embodiments, an example in which theSi-based thin film such as the SiOC film or the SiO film is formed usingthe oxidizing gas such as the H₂O gas has been described. The presentinvention is not limited thereto, and the Si-based thin film such as theSiCN film may be formed by nitriding the silicon-containing layercontaining C and Cl using a nitriding gas instead of the oxidizing gas.Alternatively, the Si-based thin film such as a SiON film or a SiOCNfilm may be formed by appropriately combining the oxidizing gas or thenitriding gas. As the nitriding gas, ammonia (NH₃) gas, diazene (N₂H₂)gas, hydrazine (N₂H₄) gas, N₃H₈ gas, a gas containing compounds ofthese, and the like may be used. At this time, the processing conditionsmay be the same processing conditions as in the above-describedembodiments.

In addition, in the above-described embodiments, an example of using thechlorosilane source gas as the source gas used in the film formation ofthe SiOC film or the SiO film has been described. The present inventionis not limited thereto, and a halosilane source gas, for example, afluorosilane source gas or a bromosilane source gas may be used insteadof the chlorosilane source gas. At this time, the processing conditionsmay be the same processing conditions as in the above-describedembodiments.

With the miniaturization of the transistor, there are demands for a lowfilm formation temperature, an improvement in resistance againsthydrogen fluoride (HF), and a reduction in the dielectric constant of athin film constituting a sidewall spacer (SWS) of a gate electrode orthe like. In addition, a protective film for a ReRAM developed as a nextgeneration memory requires low temperature film formation of 350° C. orless, and a protective film for an MRAM requires low temperature filmformation of 250° C. or less. In response to these requirements, thepresent invention is preferably applied to a case in which a thin filmsuch as the Si-based thin film (SiOC film, SiOCN film, SiCN film) andthe like is formed using the source gas containing Si, C, and a halogenelement and having the Si—C bonds, the oxidizing gas, and the like.

By using the Si-based thin film formed by the above-describedembodiments and modification examples as the SWS, device formingtechnologies in which leak current is low and processability isexcellent may be provided. In addition, by using the Si-based thin filmformed by the above-described embodiments and modification examples asan etch stopper, the device forming technologies having excellentprocessability may be provided. In addition, according to theabove-described embodiments and partial modification examples, theSi-based thin film having an ideal stoichiometric ratio may be formedwithout using plasma even in a low temperature region. Since theSi-based thin film is formed without using the plasma, it is possible toapply it to processes in which plasma damage is a concern such as in aSADP film of DPT.

In the above-described embodiments, an example of forming asilicon-based thin film (SiO film, SiOC film, SiCN film, SiON film, andSiOCN film) containing Si as a semiconductor element has been described,but the present invention is not limited thereto. For example, thepresent invention may be applied to a case of forming a metallic thinfilm containing a metal element such as titanium (Ti), zirconium (Zr),hafnium (Hf), tantalum (Ta), aluminum (Al), molybdenum (Mo), or thelike.

For example, the present invention is preferably applied to a case offorming metal oxide films such as a titanium oxide film (TiO film), azirconium oxide film (ZrO film), a hafnium oxide film (HfO film), atantalum oxide film (TaO film), an aluminum oxide film (AlO film), amolybdenum oxide film (MoO film), and the like.

In addition, the present invention is preferably applied to a case offorming metal oxycarbide films such as a titanium oxycarbide film (TiOCfilm), a zirconium oxycarbide film (ZrOC film), a hafnium oxycarbidefilm (HfOC film), a tantalum oxycarbide film (TaOC film), an aluminumoxycarbide film, a molybdenum oxycarbide film (MoOC film), and the like.

In addition, the present invention is preferably applied to a case offorming metal carbonitride films such as a titanium carbonitride film(TiCN film), a zirconium carbon nitride film (ZrCN film), a hafniumcarbonitride film (HfCN film), a tantalum carbonitride film (TaCN film),an aluminum carbonitride film, a molybdenum carbonitride film (MoCNfilm), and the like.

In addition, the present invention is preferably applied to a case offorming metal oxynitride films such as a titanium oxynitride film (TiONfilm), a zirconium oxynitride film (ZrON film), a hafnium oxynitridefilm (HfON film), a tantalum oxynitride film (TaON film), an aluminumoxynitride film, a molybdenum oxynitride film (MoON film), and the like.

In addition, the present invention is preferably applied to a case offorming metal carbonitride oxide films such as a titanium carbonitrideoxide film (TiOCN film), a zirconium carbonitride oxide film (ZrOCNfilm), a hafnium carbonitride oxide film (HfOCN film), a tantalumcarbonitride oxide film (TaOCN film), a molybdenum carbonitride oxidefilm (MoOCN film), and the like.

In this case, as a source gas, instead of the source gas containing Siin the embodiment described above, a source gas containing a metalelement is used to perform film formation according to the same sequenceas in the embodiment described above.

For example, when a metal-based thin film containing Ti (a TiO film,TiOC film, TiCN film, TiON film, or TiOCN film) is formed, as a sourcegas containing Ti, a source gas which contains Ti, C, and a halogen andhas Ti—C bonds or a source gas which contains Ti and a halogen may beused. As the source gas which contains Ti and a halogen, for example, asource gas which contains Ti and a chloro group such as titaniumtetrachloride (TiCl₄) or a source gas which contains Ti and a fluorogroup such as titanium tetrafluoride (TiF₄) may be used. As an oxidationgas, a nitriding gas, an amine-based catalyst gas, and an oxygen-freegas, the same gases as in the embodiment described above may be used.Processing conditions at this time may be the same, for example, as inthe embodiment described above.

Also, for example, when a metal-based thin film containing Zr (a ZrOfilm, ZrOC film, ZrCN film, ZrON film, or ZrOCN film) is formed, as asource gas containing Zr, a source gas which contains Zr, C, and ahalogen and has Zr—C bonds or a source gas which contains Zr and ahalogen may be used. As the source gas which contains Zr and a halogen,for example, a source gas which contains Zr and a chloro group such aszirconium tetrachloride (ZrCl₄) or a source gas which contains Zr and afluoro group such as zirconium tetrafluoride may be used. As anoxidation gas, a nitriding gas, an amine-based catalyst gas, and anoxygen-free gas, the same gases as in the embodiment described above maybe used. Processing conditions at this time may be the same, forexample, as in the embodiment described above.

Also, for example, when a metal-based thin film containing Hf (a HfOfilm, HfOC film, HfCN film, HfON film, or HfOCN film) is formed, as asource gas containing Hf, a source gas which contains Hf, C, and ahalogen and has Hf—C bonds or a source gas which contains Hf and ahalogen may be used. As the source gas which contains Hf and a halogen,for example, a source gas which contains Hf and a chloro group such ashafnium tetrachloride (HfCl₄) or a source gas which contains Hf and afluoro group such as hafnium tetrafluoride (HfF₄) may be used. As anoxidation gas, a nitriding gas, an amine-based catalyst gas, and anoxygen-free gas, the same gases as in the embodiment described above maybe used. Processing conditions at this time may be the same, forexample, as in the embodiment described above.

Also, for example, when a metal-based thin film containing Ta (a TaOfilm, TaOC film, TaCN film, TaON film, or TaOCN film) is formed, as asource gas containing Ta, a source gas which contains Ta, C, and ahalogen and has Ta—C bonds or a source gas which contains Ta and ahalogen may be used. As the source gas which contains Ta and a halogen,for example, a source gas which contains Ta and a chloro group such astantalum pentachloride (TaCl₅) or a source gas which contains Ta and afluoro group such as tantalum pentafluoride (TaF₅) may be used. As anoxidation gas, a nitriding gas, an amine-based catalyst gas, and anoxygen-free gas, the same gases as in the embodiment described above maybe used. Processing conditions at this time may be the same, forexample, as in the embodiment described above.

Also, for example, when a metal-based thin film containing Al (an AlOfilm, AlOC film, AlCN film, AlON film, or AlOCN film) is formed, as asource gas containing Al, a source gas which contains Al, C, and ahalogen and has Al—C bonds or a source gas which contains Al and ahalogen may be used. As the source gas which contains Al and a halogen,for example, a source gas which contains Al and a chloro group such asaluminum trichloride (AlCl₃) or a source gas which contains Al and afluoro group such as aluminum trifluoride (AlF₃) may be used. As anoxidation gas, a nitriding gas, an amine-based catalyst gas, and anoxygen-free gas, the same gases as in the embodiment described above maybe used. Processing conditions at this time may be the same, forexample, as in the embodiment described above.

Also, for example, when a metal-based thin film containing Mo (a MoOfilm, MoOC film, MoON film, or MoOCN film) is formed, as a source gascontaining Mo, a source gas which contains Mo, C, and a halogen and hasMo—C bonds or a source gas which contains Mo and a halogen may be used.As the source gas which contains Mo and a halogen, for example, a sourcegas which contains Mo and a chloro group such as molybdenumpentachloride (MoCl₅) or a source gas which contains Mo and a fluorogroup such as molybdenum pentafluoride (MoF₅) may be used. As anoxidation gas, a nitriding gas, an amine-based catalyst gas, and anoxygen-free gas, the same gases as in the embodiment described above maybe used. Processing conditions at this time may be the same, forexample, as in the embodiment described above.

That is, the present invention may be preferably applied when a thinfilm containing a predetermined element such as a semiconductor elementor a metal element is formed. In addition, if a thin film includes water(H₂O) and chlorine (Cl) as the first impurities and includes ahydrocarbon compound (C_(x)H_(y)-based impurities) as the secondimpurities, the modifying process of the present invention may bebroadly applied without being limited to the film formation method orthe film type described above.

It is preferable that a process recipe (a program storing processingprocedures or processing conditions) used for film formation of thesevarious thin films be individually prepared (a plurality of recipes areprepared) according to content (such as a film type of a thin film to beformed, a composition ratio, a film quality, a film thickness, a sourcegas, an oxidation gas, a catalyst gas, and a kind of oxygen-free gas) ofsubstrate processing. Then, when the substrate processing starts, it ispreferable that an appropriate process recipe be appropriately selectedfrom among the plurality of process recipes according to the content ofsubstrate processing. Specifically, it is preferable that the pluralityof process recipes individually prepared according to the content ofsubstrate processing be pre-stored (installed) in the memory device 121c included in the substrate processing apparatus through electricalcommunication lines or a non-transitory computer-readable recordingmedium (the external memory device 123) recording the process recipe.Then, when the substrate processing starts, it is preferable that theCPU 121 a included in the substrate processing apparatus appropriatelyselect an appropriate process recipe according to the content ofsubstrate processing from among the plurality of process recipes storedin the memory device 121 c. In such a configuration, using a singlesubstrate processing apparatus, it is possible to generally form thinfilms having various film types, composition ratios, film qualities, andfilm thicknesses in good reproducibility. Also, it is possible to reducea burden of manipulation (such as a burden of inputting processingprocedures or processing conditions) on an operator. Accordingly, it ispossible to rapidly start the substrate processing while preventingmanipulation errors.

The process recipe described above is not limited to a newly createdrecipe, but may be prepared by, for example, modifying an existingprocess recipe already installed in the substrate processing apparatus.When the process recipe is modified, the modified process recipe may beinstalled in the substrate processing apparatus through the electricalcommunication lines or the non-transitory computer-readable recordingmedium recording the process recipe. Also, the existing process recipealready installed in the substrate processing apparatus may be directlymodified by manipulating the input/output device 122 included in theexisting substrate processing apparatus.

Also, in the film formation sequence in the embodiment described aboveand the like, the example in which the SiOC film, the SiO film, thestacked film, and the like are formed at a room temperature has alsobeen described. In this case, there is no need to heat the inside of theprocessing chamber 201 using the heater 207 and the heater 207 need notbe installed in the substrate processing apparatus. Thereby, it ispossible to simplify a configuration of the heating system of thesubstrate processing apparatus and it is possible to build a simple andless expensive substrate processing apparatus. In this case, themodifying process of the SiOC film, the SiO film, the stacked film, andthe like may be performed in a processing chamber that is different fromthe processing chamber performing the process of forming the SiOC film,the SiO film, the stacked film, and the like, ex situ.

In the embodiment described above and the like, the example in which themodifying process (annealing process) of the SiOC film, the SiO film,the stacked film, and the like is performed by heating of the resistanceheating-type heater 207 has been described. The present invention is notlimited thereto. For example, the above-described modifying process maybe performed by radiating plasma, ultraviolet light, microwaves, and thelike. That is, the above-described modifying process may be performedusing heat transmission from the heater 207 and may also be performedusing an activating device using plasma, electromagnetic waves, and thelike rather than heat. In this case, the same effects as in theembodiment described above and the like may also be obtained.

When the above-described modifying process is performed by radiating theplasma, for example, a capacitively coupled plasma generator, aninductively coupled plasma generator, an electron cyclotron resonator, asurface wave plasma generator, a helicon wave plasma generator, and thelike may be used as the activating device instead of the heater 207.Also, these devices may be used in combination with the heater 207.Using these devices, in the buffer chamber in the processing chamber 201or outside the processing chamber 201, plasma obtained by convertinggases such as He, Ar, and N₂ into plasma, that is, quasi-neutral gasesis composed of charged particles and neutral particles that behavecollectively, is radiated onto the wafer 200 in the processing chamber201, and thereby the above-described modifying process may be performed.

When the above-described modifying process is performed by radiating theultraviolet light, for example, a deuterium lamp, a helium lamp, acarbon-arc lamp, a BRV light source, an excimer lamp, a mercury lamp,and the like may be used as the activating device instead of the heater207. Also, these devices may be used in combination with the heater 207.From these light sources, for example, vacuum ultraviolet light having awavelength of 10 nm to 200 nm is radiated onto the wafer 200 in theprocessing chamber 201, and thereby the above-described modifyingprocess may be performed.

When the above-described modifying process is performed by radiating themicrowaves, for example, a microwave generator generatingelectromagnetic waves having a wavelength of 100 μm to 1 m and afrequency of 3 THz to 300 MHz may be used as the activating deviceinstead of the heater 207. Also, these devices may be used incombination with the heater 207. The microwaves having the wavelengthdescribed above are radiated onto the wafer 200 in the processingchamber 201, act in the SiOC film, the SiO film, the stacked film, andthe like, that is, act on electronic polarization or ionic polarizationin a dielectric material, and generate induction heating, therebyperforming the above-described modifying process.

In this case, the processing conditions may also be the same, forexample, as in the embodiment or modification example described above.

In the embodiment described above and the like, the example in which thebatch-type substrate processing apparatus that processes a plurality ofsubstrates at once is used for film formation of the thin film has beendescribed. The present invention is not limited thereto but may bepreferably applied when a single-wafer substrate processing apparatusthat processes a single substrate or several substrates at one time isused to form the thin film. Also, in the embodiment described above, theexample in which the substrate processing apparatus including a hotwall-type processing furnace is used to form the thin film has beendescribed. The present invention is not limited thereto but may also bepreferably applied when a substrate processing apparatus including acold wall-type processing furnace is used to form the thin film.Processing conditions at this time may be the same, for example, as inthe embodiment described above.

The embodiments and modification examples described above may beappropriately combined and used. Also, the processing conditions at thistime may be the same, for example, as in the embodiment described above.

Examples

First Example

As an example of the present invention, a SiOC film was formed on awafer using the substrate processing apparatus according to theabove-described embodiment and according to the film forming sequence ofFIG. 4A according to the previous embodiment, and variouscharacteristics of the SiOC film were evaluated by performing amodification process on the SiOC film. The forming of the SiOC film andthe modification process were performed in different processingchambers, i.e., ex situ. In the modification process, a first thermaltreatment was not performed and only a second thermal treatment wasperformed. BTCSM gas was used as a source gas, H₂O gas was used as anoxidizing gas, a pyridine gas was used as a catalyst gas, and N₂ gas wasused as a heat treatment gas during the modification process. Processconditions were the same as those in the previous embodiments.

FIGS. 11A through 11C are graphs showing results of evaluating thepresent example. In detail, FIG. 11A is a graph illustrating relativedielectric constants of the SiOC film before and after a heat treatmentwas performed. FIG. 11B is a graph showing wet etching rates (WERs) ofthe SiOC film before and after the heat treatment was performed. FIG.11C is a graph showing temperature dependence of heat treatment of thewet etching rate of the SiOC film.

In FIG. 11A, the vertical axis of the graph denotes processed states ofthe SiOC film, in which an example of a SiOC film that was formed bysetting the temperature of a wafer to 60° C. and was not thermallytreated (60° C. as depo) and an example of a SiOC film that was formedby setting the temperature of the wafer to 60° C. and was thermallytreated under a N₂ gas atmosphere for thirty minutes by setting thetemperature of the wafer to 600° C. (600° C., 30 min, N₂ annealing) areshown sequentially from the left. Also, the vertical axis of the graphdenotes a variation in a relative dielectric constant (k value) of theSiOC film. The relative dielectric constant of the SiOC film is theratio of the dielectric constant ∈ of the SiOC film to the dielectricconstant ∈₀ of vacuum, i.e., ∈r=∈/∈₀.

Referring to FIG. 11A, in the present example, the relative dielectricconstant of the SiOC film that had yet to be thermally treated was 7.76.Also, another evaluation conducted by the inventors of the presentapplication showed that a SiOC film formed at a relatively hightemperature had a relative dielectric constant of about 4.5. Therelative dielectric constant of the SiOC film that had yet to bethermally treated according to the present example was higher than thatof the SiOC film that was thermally treated. Specifically, in thepresent example, the relative dielectric constant of the SiOC film thatwas thermally treated was 3.58 and was thus much lower than the relativedielectric constant of about 4.5 of the SiOC film formed at therelatively high temperature described above or the relative dielectricconstant of about 3.9 of a general thermal oxide film. This isconsidered to be mainly due to the fact that materials that increase thedielectric constant of the SiOC film e.g., impurities such as moistureor chlorine (Cl), in the SiOC film formed under low-temperatureconditions were removed from the SiOC film when the SiOC film wasthermally treated, and the SiOC film was formed in a porous state.

In FIG. 11B, the horizontal axis of the graph is the same as that ofFIG. 11A, in which an example of a SiOC film (60° C., as depo) and anexample of a SiOC film (600° C., 30 min, N₂, annealing) are sequentiallyshown from the left. Also, the vertical axis of the graph denotes theWER (expressed in a.u.) of the SiOC film when a solution containing 1%hydrofluoric acid (1% HF aqueous solution) was used. Here, ‘WER’ denotesan etched depth per unit hour. The lower the WER, the higher thetolerance to HF (i.e., etching resistance).

Referring to FIG. 11B, the WER of the SiOC film that had yet to bethermally treated shows that the SiOC film has a relatively high etchingresistance. In another evaluation, the inventors of the presentapplication found that the WER of the SiOC film was lower than that of aSiO film formed under low-temperature conditions. Also, referring toFIG. 11B, the WER of the SiOC film that was thermally treated was ⅛ ofthe WER of the SiOC film that had yet to be thermally treated, and waslower than the WER of a general thermal oxide film. That is, the etchingresistance of the SiOC film can be improved by reducing the amount ofimpurities in the SiOC film by thermally treating the SiOC film.

In FIG. 11C, the horizontal axis of the graph denotes temperatureconditions of a thermal treatment of a SiOC film that was formed bysetting the temperature of the wafer to 60° C. and then thermallytreated under a N₂ gas atmosphere for thirty minutes, in which cases inwhich the SiOC film was thermally treated at 200° C., 300° C., 500° C.,600° C., and 630° C. are sequentially shown from the left. The verticalaxis of the graph denotes the WER (expressed in a.u.) of the SiOC filmwhen a 1% HF aqueous solution was used, similar to FIG. 11B.

Referring to FIG. 11C, the WER of the SiOC film when the SiOC film wasthermally treated at 200° C. caused a desired effect to be achieved whena modification process was performed. Also, referring to FIG. 11C, theWER of the SiOC film when the SiOC film was thermally treated at 300° C.was about half the WER of the SiOC film when the SiOC film was thermallytreated at 200° C., and a desired effect was also achieved. Also, theWER of the SiOC film was greatly lowered when the SiOC film wasthermally treated at 500° C., and a more desired effect was achievedthan when the SiOC film was thermally treated at a temperature higherthan 500° C., e.g., 600° C. or 630° C. All of the WERs of the SiOC filmwhen the SiOC film was thermally treated at 500° C., 600° C., and 630°C. were about 1/10 or less of the WER of the SiOC film when the SiOCfilm was thermally treated at 200° C. Accordingly, the etchingresistance of the SiOC film when the SiOC film is thermally treated atat least 500° C. or more can be improved. Also, a reduction in the WERof the SiOC film was slowed at 500° C. or more but the WER of the SiOCfilm was greatly lowered at 630° C. The WER of the SiOC film at 630° C.was about 70% of the WER of the SiOC film at 500° C. Thus, the etchingresistance of the SiOC film is expected to be greatly increased when atemperature at which the SiOC film is to be thermally treated is set to630° C. or more. Accordingly, an effect of reducing the WER of SiOC filmcan be greatly increased by increasing a temperature at which the SiOCfilm is to be thermally treated.

Second Example

As another example of the present invention, a SiOC film was formed on awafer using the substrate processing apparatus according to the previousembodiment and according to the film forming sequence of FIG. 4Aaccording to the previous embodiment, and a modification process wasthen performed on the SiOC film. The forming of the SiOC film and themodification process were performed in different processing chambers,i.e., ex situ.

Here, in an annealing sequence of FIG. 14A, a sample (Sample 1) on whichboth a first thermal treatment and a second thermal treatment wereperformed as a modification process and a sample (Sample 2) on which thefirst thermal treatment was not performed and only the second thermaltreatment was performed were prepared. Then various characteristics ofthe SiOC film in Samples 1 and 2 were evaluated.

When Samples 1 and 2 were prepared, BTCSM gas was used as a source gas,H₂O gas was used as an oxidizing gas, a pyridine gas was used as acatalyst gas, and N₂ gas was used as a heat treatment gas during themodification process. Process conditions were the same as those in theprevious embodiments. The temperature (first temperature) of the waferwas set to 450° C. when the first thermal treatment was performed onSample 1, and the temperature (second temperature) of the wafer was setto 600° C. when the second thermal treatment was performed on Samples 1and 2. The other process conditions were the same as those in theprevious embodiments.

FIG. 13 is a table showing a result of evaluating the second example, inwhich various characteristics, e.g., WERs, shrinking rates (contractionpercentages), k values (relative dielectric constants), etc. of the SiOCfilm of Sample 1 and the SiOC film of Sample 2 are compared.

Referring to FIG. 13, the WER of the SiOC film of Sample 1 is 1/17 ofthe WER of the SiOC film of Sample 2 or more. That is, the WER of theSiOC film of Sample 1 is far lower than the WER of the SiOC film ofSample 2. Also, the WER of the SiOC film of Sample 2 is relatively lowand thus the SiOC film of Sample 2 has a relatively high etchingresistance. That is, the WER of the SiOC film of Sample 1 is much lowerthan a low WER (the WER of the SiOC film of Sample 2), and thus the SiOCfilm of Sample 1 has a high etching resistance that is much higher thana high etching resistance (the etching resistance of the SiOC film ofSample 2). This is considered to be due to the fact that impurities suchas moisture or chlorine (Cl) were removed from the SiOC film of Sample 2when the second thermal treatment was performed thereon, and not onlyimpurities such as moisture or chlorine (Cl) but also C_(x)H_(y)-basedimpurities were sufficiently removed from the SiOC film of Sample 1 whenthe first and second thermal treatments were sequentially performedthereon.

Also, referring to FIG. 13, the shrinking rate of the SiOC film ofSample 1 is about 9/10 of that of the SiOC film of Sample 2, i.e., theshrinking rate of the SiOC film of Sample 1 is lower than that of theSiOC film of Sample 2. Here, the shrinking rate means the ratio of thecontraction percentage of the SiOC film that was modified to thecontraction percentage of the SiOC film that had yet to be modified,i.e., a contraction rate of the SiOC film when the modification processwas performed thereon. That is, the SiOC film of Sample 1 contractedless when the modification process was performed thereon than the SiOCfilm of Sample 2 when the modification process was performed thereon. Inother words, the SiOC film of Sample 2 contracted when a modificationprocess was performed thereon more than the SiOC film of Sample 1 whenthe modification process was performed thereon.

The shrinking rate of the SiOC film of Sample 1 was considered to be lowbecause the first and second thermal treatments were sequentiallyperformed on the SiOC film of Sample 1, i.e., a two-step thermaltreatment was performed at different temperatures, and the SiOC filmcould be suppressed from being oxidized due to moisture or chlorine (Cl)separated from the SiOC film, thereby suppressing a reduction in thecontraction rate of the SiOC film. Also, the shrinking rate of the SiOCfilm of Sample 2 was considered to be high because only the secondthermal treatment was performed on the SiOC film of Sample 2 withoutperforming the first thermal treatment, i.e., a one-step thermaltreatment was performed at a relatively high temperature, and the SiOCfilm was oxidized due to moisture or chlorine (Cl) separated from theSiOC film, thereby causing the SiOC film to easily contract.

Also, referring to FIG. 13, the relative dielectric constant of 2.68 ofthe SiOC film of Sample 1 is lower than the relative dielectric constantof 3.58 of the SiOC film of Sample 2. Also, the relative dielectricconstant of 3.58 of the SiOC film of Sample 2 is much lower than therelative dielectric constant of about 3.9 of a general thermal oxidefilm, but the relative dielectric constant of 2.68 of the SiOC film ofSample 1 is still much lower than the relative dielectric constant ofabout 3.9 of the general thermal oxide film.

The relative dielectric constant of the SiOC film of Sample 2 isconsidered to be much lower than that of the general thermal oxide filmbecause materials that increase the dielectric constant of the SiOCfilm, e.g., impurities such as moisture or chlorine (Cl), in the SiOCfilm were removed from the SiOC film when the second thermal treatmentwas performed on the SiOC film, and the SiOC film was formed in a porousstate. The relative dielectric constant of the SiOC film of Sample 1 isconsidered to be even lower than that of the general thermal oxide filmor that of the SiOC film of Sample 2 mainly due to the fact that notonly materials that increase the dielectric constant of the SiOC film,e.g., impurities such as moisture or chlorine (Cl), but alsoC_(x)H_(y)-based impurities were sufficiently removed from the SiOC filmwhen the first and second thermal treatments, i.e., a two-step thermaltreatment performed at different temperatures, were performed on theSiOC film, and the porous state of the SiOC film was intensified.

Third Embodiment

As another example of the present invention, a SiOC film was formed on awafer using the substrate processing apparatus according to the previousembodiment and according to the film forming sequence of FIG. 4Aaccording to the previous embodiment and a modification process was thenperformed on the SiOC film. The forming of the SiOC film and themodification process were performed in different processing chambers,i.e., ex situ.

Here, a sample (Sample 1) was prepared by forming a film by setting thetemperature of a wafer to 60° C. and thermally treating the film under aN₂ gas atmosphere by setting the temperature of the wafer to 100° C. Asample (Sample 2) was prepared by forming a film by setting thetemperature of the wafer to 60° C. and thermally treating the film underthe N₂ gas atmosphere as the modification process by setting thetemperature of the wafer to 200° C. A sample (Sample 3) was prepared byforming a film by setting the temperature of the wafer to 60° C. andperforming a first thermal treatment and a second thermal treatment as amodification process on the film in an annealing sequence of FIG. 15.Samples (Samples 4 to 6) were each prepared by forming a film by settingthe temperature of the wafer to 60° C. and performing the first andsecond thermal treatments as a modification process on the film in theannealing sequence of FIG. 14. Then, the WER of a SiOC film of each ofthe samples was evaluated.

When Samples 1 to 6 were prepared, BTCSM gas was used as a source gas,H₂O gas was used as an oxidizing gas, a pyridine gas was used as acatalyst gas, and N₂ gas was used as a heat treatment gas when themodification process was performed on the SiOC film. Process conditionswere the same as those in the previous embodiments. The temperatures(first and second temperatures) of the wafer were set to 300° C. whenthe first and second thermal treatments were performed on Sample 3. Thetemperatures (first temperature) of the wafer were set to 450° C. whenthe first thermal treatment was performed on Samples 4 to 6. Thetemperatures (second temperature) of the wafer were set to 500° C., 600°C., and 630° C. when the second thermal treatment was performed onSamples 4 to 6, respectively. Other conditions, e.g., durations forwhich the first temperature and the second temperature were maintained,a time required to increase or decrease a temperature, etc., are asshown in the table of FIG. 16B. The other process conditions were thesame as those in the previous embodiments.

FIG. 16A is a graph showing the WERs of Samples 1 to 6. FIG. 16B is atable comparing the conditions of thermal treatments performed onSamples 1 to 6. In FIG. 16A, the horizontal axis denotes Samples 1 to 6,and the vertical axis denotes the WER (expressed in A/min) of a SiOCfilm when a 1% HF aqueous solution was used.

Referring to FIG. 16A, the SiOC films of Samples 2 to 6 have WERs thatare much lower than that of the SiOC film of Sample 1, i.e., they havemuch higher etching resistances than the SiOC film of Sample 1.Particularly, in the case of Samples 3 to 6 for which first and secondtemperatures were set to be in the temperature range of the previousembodiment, the WERs are very low and the etching resistances are veryhigh. Also, when Samples 4 to 6 for which a second temperature was setto be higher than a first temperature are compared with of Sample 3 forwhich a second temperature was substantially the same as a firsttemperature, the WERs of Samples 4 to 6 are lower than that of Sample 3and the etching resistances of Samples 4 to 6 are higher than that ofSample 3. This is considered to be mainly due to the fact that the firstthermal treatment and the second thermal treatment were performed withinthe range of the conditions in the previous embodiments to sufficientlyremove not only first impurities such as moisture or chlorine (Cl) butalso C_(x)H_(y)-based second impurities from the SiOC film.

Fourth Embodiment

As another example of the present invention, a SiOC film was formed on awafer using the substrate processing apparatus according to the previousembodiment and according to the film forming sequence of FIG. 4Aaccording to the previous embodiment and a modification process was thenperformed on the SiOC film. The forming of the SiOC film and themodification process were performed in different processing chambers,i.e., ex situ.

Here, a sample (Sample 1) was prepared by forming a SiOC film by settingthe temperature of a wafer to 60° C. Samples (Samples 2 to 4) wereprepared by forming a SiOC film by setting the temperature of a wafer to60° C. and a first thermal treatment and a second thermal treatment wereperformed in the annealing sequence of FIG. 15. Samples (Samples 5 to 8)were prepared by forming a SiOC film by setting the temperature of awafer to 60° C. and the first thermal treatment and the second thermaltreatment were performed in the annealing sequence of FIG. 14A. Then,the relative dielectric constants of the SiOC films of Samples 1 to 8were evaluated.

When Samples 1 to 8 were prepared, BTCSM gas was used as a source gas,H₂O gas was used as an oxidizing gas, a pyridine gas was used as acatalyst gas, and N₂ gas was used as a heat treatment gas when themodification process was performed on the SiOC films. The temperatures(=first temperatures=second temperatures) of the wafer when the firstand second thermal treatments were performed on Samples 2 to 4 were setto 300° C., 400° C., and 600° C., respectively. The temperature (firsttemperature) of the wafer was set to 60° C. when the first thermaltreatment was performed on Sample 5, and the temperature (secondtemperature) of the wafer was set to 200° C. when the second thermaltreatment was performed on Sample 5. The temperatures (firsttemperatures) of the wafer were set to 450° C. when the first thermaltreatment was performed on Samples 6 to 8, and the temperatures (secondtemperatures) of the wafer were set to 500° C., 630° C., and 700° C.,respectively, when the second thermal treatment was performed on Samples6 to 8. The other process conditions were the same as those in theprevious embodiments.

Also, as a reference example, a SiO film was formed on a wafer accordingto a film forming sequence of alternately performing, a predeterminednumber of times, supplying a source gas and a catalyst gas and supplyingan oxidizing gas and a catalyst gas, and then a modification process wasperformed on the SiO film. The forming of the SiO film and themodification process were performed in different processing chambers,i.e., ex situ.

Here, a sample (Sample 9) was prepared by forming a SiO film by settingthe temperature of the wafer to 60° C., and a sample (Sample 10) wasprepared by forming a SiO film by setting the temperature of the waferto 60° C. and performing only the second thermal treatment as themodification process on the SiO film without performing the firstthermal treatment. Then, the relative dielectric constants of the SiOfilms of Samples 9 and 10 were evaluated.

When Samples 9 and 10 were prepared, HCDS gas was used as a source gas,H₂O gas was used as an oxidizing gas, a pyridine gas was used as acatalyst gas, and N₂ gas was used as a heat treatment gas when themodification process is performed. The temperature (second temperature)of the wafer was set to 600° C. when the second thermal treatment wasperformed on Sample 10. The other conditions were the same as those inthe previous embodiments.

FIG. 17 is a graph showing the relative dielectric constants (k values)of Samples 1 to 10. In the graph of FIG. 17, the horizontal axis denotesthe temperature (expressed in ° C.) of a wafer when the second thermaltreatment was performed and the vertical axis denotes the relativedielectric constants of Samples 1 to 10. In FIG. 17, for convenience ofexplanation, Samples 1 to 10 are illustrated as S1 to S10, respectively.

Referring to FIG. 17, the relative dielectric constants of the SiOCfilms of Samples 2 to 8 are lower than that of the SiOC film of Sample 1or that of the SiO film of Sample 9. In particular, the relativedielectric constants of Samples 3, 4, and 6 to 8 for which first andsecond temperatures were set to be in the ranges of the temperatures inthe previous embodiments are still much lower. Also, the relativedielectric constants of the SiOC films of Samples 3 4 and 6 to 8 arelower than that of the SiO film of Sample 10. Also, the relativedielectric constants of the SiOC films of Samples 6 to 8 are lower than‘3.’ This is considered to be mainly due to the fact that the firstthermal treatment and the second thermal treatment were performed withinthe range of the conditions in the previous embodiments to sufficientlyremove not only impurities such as moisture or chlorine (Cl) but alsoC_(x)H_(y)-based impurities, which are materials that increase thedielectric constant of the SiOC film, from the SiOC film formed underlow-temperature conditions and that the SiOC film was formed in a porousstate.

According to the one or more embodiments of the invention set forthhere, a thin film of a low dielectric constant having excellent etchingresistance can be formed.

Preferred Embodiments of the Present Invention

The following supplementary notes are added herein as exemplaryembodiments of the present invention.

Supplementary Note 1

According to one aspect of the present invention, there are provided amethod of manufacturing a semiconductor device, including: (a) forming athin film on a substrate; (b) removing first impurities containing water(H₂O) and chlorine (Cl) from the thin film by heating the thin film at afirst temperature higher than a temperature of the substrate in the step(a); and (c) removing second impurities (C_(x)H_(y)-based impurities)containing a hydrocarbon compound from the thin film by heating the thinfilm at a second temperature equal to or higher than the firsttemperature after performing the step (b).

Supplementary Note 2

In the method described in supplementary note 1, it is preferable thatthe step (b) includes at least a part of a period of raising thetemperature of the substrate to the first temperature.

Supplementary Note 3

In the method described in supplementary note 1 or 2, it is preferablethat the step (b) includes a period of maintaining the temperature ofthe substrate at the first temperature.

Supplementary Note 4

In the method described in any one of supplementary notes 1 to 3, it ispreferable that the second temperature is higher than the firsttemperature. In addition, the step (c) preferably includes at least apart of a period of raising the temperature of the substrate to thesecond temperature.

Supplementary Note 5

In the method described in any one of supplementary notes 1 to 4, it ispreferable that the step (c) includes a period of maintaining thetemperature of the substrate at the second temperature.

Supplementary Note 6

In the method described in any one of supplementary notes 1 to 5, it ispreferable that the step (c) includes at least a part of a period oflowering the temperature of the substrate from the second temperature.

Supplementary Note 7

In the method described in any one of supplementary notes 1 to 3, it ispreferable that the second temperature is substantially equal to (isequal to) the first temperature. In addition, the step (c) preferablyincludes a period of maintaining the temperature of the substrate at thefirst temperature.

Supplementary Note 8

In the method described in any one of supplementary notes 1 to 7, it ispreferable that the first impurities are removed from the thin film atthe first temperature without oxidizing the thin film. In addition, itis preferable that the first impurities are removed from the thin filmat the first temperature without reacting with impurities different fromthe first impurities and contained in the thin film. Further, it ispreferable that the first impurities are removed from the thin film atthe first temperature without reacting with the second impuritiescontained in the thin film.

Supplementary Note 9

In the method described in any one of supplementary notes 1 to 8, thefirst temperature ranges preferably from 300° C. to 450° C., morepreferably from 300° C. to 400° C., and still more preferably from 300°C. to 350° C.

Supplementary Note 10

In the method described in any one of supplementary notes 1 to 9, thesecond temperature ranges preferably from 300° C. to 900° C., morepreferably from 350° C. to 700° C., more preferably 400° C. to 700° C.,and still more preferably from 450° C. to 600° C.

Supplementary Note 11

In the method described in any one of supplementary notes 1 to 10, it ispreferable that the thin film contains a predetermined element, oxygenand carbon.

Supplementary Note 12

In the method described in supplementary note 11, it is preferable thatthe step (a) includes performing a cycle a predetermined number oftimes, the cycle including: (a-1) supplying a source gas containing thepredetermined element, carbon and halogen element and having a chemicalbond between the predetermined element and the carbon to the substrate,(a-2) supplying an oxidizing gas to the substrate, and (a-3) supplying acatalyst gas to the substrate.

Supplementary Note 13

In the method described in supplementary note 12, the temperature of thesubstrate in the step (a) ranges preferably from a room temperature to150° C., more preferably from a room temperature to 100° C., and stillmore preferably from 50° C. to 100° C.

Supplementary Note 14

In the method described in supplementary note 12 or 13, it is preferablethat the predetermined element includes silicon (Si), and the source gasincludes at least one selected from a group consisting of a Si—C bond, aSi—C—Si bond and a Si—C—C—Si bond.

Supplementary Note 15

In the method described in any one of supplementary notes 1 to 14, it ispreferable that each of the steps (b) and (c) is performed in anoxygen-free atmosphere by supplying an oxygen-free gas to the substrate.In addition, it is preferable that the thin film is heated in an inertgas atmosphere by supplying an inert gas to the substrate in the steps(a) and (b).

Supplementary Note 16

In the method described in any one of supplementary notes 1 to 15, it ispreferable that the step (a) and the film-heating steps (i.e., the steps(b) and (c)) are performed in a same processing chamber or in differentprocessing chambers.

Supplementary Note 17

According to another aspect of the present invention, there is provideda substrate processing apparatus including: a processing chamberconfigured to accommodate a substrate; a processing gas supply systemconfigured to supply a processing gas into the processing chamber toform a thin film on the substrate; a heater configured to heat thesubstrate in the processing chamber; and a control unit configured tocontrol the processing gas supply system and the heater to perform (a)forming the thin film on the substrate by supplying the processing gasto the substrate in the processing chamber, (b) removing firstimpurities containing water (H₂O) and chlorine (Cl) from the thin filmby heating the thin film at a first temperature higher than atemperature of the substrate in the step (a), and (c) removing secondimpurities (C_(x)H_(y)-based impurities) containing a hydrocarboncompound from the thin film by heating the thin film at a secondtemperature equal to or higher than the first temperature afterperforming the step (b).

Supplementary Note 18

According to still another aspect of the present invention, there isprovided a substrate processing system including: a first substrateprocessing unit configured to form a thin film on a substrate; and asecond substrate processing unit configured to perform heat treatment onthe thin film, wherein the first substrate processing unit includes: afirst processing chamber configured to accommodate a substrate; aprocessing gas supply system configured to supply a processing gas intothe first processing chamber; and a first control unit configured tocontrol the processing gas supply system to form the thin film on thesubstrate by supplying the processing gas to the substrate in the firstprocessing chamber; and wherein the second substrate processing unitincludes: a second processing chamber configured to accommodate thesubstrate; a heater configured to heat the substrate in the secondprocessing chamber; and a second control unit configured to control theheater to perform (a) removing first impurities containing water (H₂O)and chlorine (Cl) from the thin film by heating the thin film at a firsttemperature higher than a temperature of the substrate in a process offorming the thin film in a state in which the second processing chamberaccommodates the substrate on which the thin film is formed, and (b)removing second impurities (C_(x)H_(y)-based impurities) containing ahydrocarbon compound from the thin film by heating the thin film at asecond temperature equal to or higher than the first temperature afterperforming the step (a).

Supplementary Note 19

According to yet another aspect of the present invention, there isprovided a non-transitory computer-readable recording medium storing aprogram that causes a computer to execute: (a) forming a thin film on asubstrate in a processing chamber; (b) removing first impuritiescontaining water (H₂O) and chlorine (Cl) from the thin film by heatingthe thin film at a first temperature higher than a temperature of thesubstrate in the sequence (a); and (c) removing second impurities(C_(x)H_(y)-based impurities) containing a hydrocarbon compound from thethin film by heating the thin film at a second temperature equal to orhigher than the first temperature after performing the sequence (b).

What is claimed is:
 1. A method of manufacturing a semiconductor device,comprising: (a) forming a thin film on a substrate; (b) removing firstimpurities containing H₂O and Cl from the thin film by heating the thinfilm at a first temperature higher than a temperature of the substratein (a); and (c) removing second impurities containing a hydrocarboncompound from the thin film by heating the thin film at a secondtemperature equal to or higher than the first temperature afterperforming (b).
 2. The method of claim 1, wherein (b) includes at leasta part of a period of raising the temperature of the substrate to thefirst temperature.
 3. The method of claim 1, wherein (b) includes aperiod of maintaining the temperature of the substrate at the firsttemperature.
 4. The method of claim 1, wherein the second temperature ishigher than the first temperature.
 5. The method of claim 1, wherein (c)includes at least a part of a period of raising the temperature of thesubstrate to the second temperature.
 6. The method of claim 1, wherein(c) includes a period of maintaining the temperature of the substrate atthe second temperature.
 7. The method of claim 1, wherein (c) includesat least a part of a period of lowering the temperature of the substratefrom the second temperature.
 8. The method of claim 1, wherein thesecond temperature is substantially equal to the first temperature. 9.The method of claim 1, wherein (c) includes a period of maintaining thetemperature of the substrate at the first temperature.
 10. The method ofclaim 1, wherein the first impurities are removed from the thin film atthe first temperature without oxidizing the thin film.
 11. The method ofclaim 1, wherein the first impurities are removed from the thin film atthe first temperature without reacting with impurities different fromthe first impurities and contained in the thin film.
 12. The method ofclaim 1, wherein the first impurities are removed from the thin film atthe first temperature without reacting with the second impuritiescontained in the thin film.
 13. The method of claim 1, wherein the firsttemperature ranges from 300° C. to 450° C.
 14. The method of claim 1,wherein the second temperature ranges from 300° C. to 900° C.
 15. Themethod of claim 1, wherein the thin film contains a predeterminedelement, oxygen and carbon.
 16. The method of claim 15, wherein (a)includes performing a cycle a predetermined number of times, the cycleincluding: supplying a source gas containing the predetermined element,carbon and halogen element and having a chemical bond between thepredetermined element and the carbon to the substrate; supplying anoxidizing gas to the substrate; and supplying a catalyst gas to thesubstrate.
 17. The method of claim 1, wherein each of (b) and (c) isperformed in an oxygen-free atmosphere by supplying an oxygen-free gasto the substrate.
 18. A non-transitory computer-readable recordingmedium storing a program that causes a computer to execute: (a) forminga thin film on a substrate in a processing chamber; (b) removing firstimpurities containing H₂O and Cl from the thin film by heating the thinfilm at a first temperature higher than a temperature of the substratein the sequence (a); and (c) removing second impurities containing ahydrocarbon compound from the thin film by heating the thin film at asecond temperature equal to or higher than the first temperature afterperforming the sequence (b).